script: re-license script from GPLv3+ to GPLv2+

Change license of mb, mlprof, modulecmd, mpub, mrel, mt, mtreview,
nglfar2ccov and playdemo scripts from GPLv3+ to GPLv2+.

Align this way all files from the Modules project under the GPLv2+
license.

Consent has been obtained from copyright holder to perform such move (I
hold the full copyright for these script files).

Related to #389

script/mb

@@ -1,11 +1,11 @@
 #!/usr/bin/env tclsh
 #
 # MB, make bench between modulecmd versions
-# Copyright (C) 2019-2020 Xavier Delaruelle
+# Copyright (C) 2019-2021 Xavier Delaruelle
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
+# the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,

script/mlprof

@@ -1,11 +1,11 @@
 #!/usr/bin/env tclsh
 #
 # MLPROF, profile a given modulecmd execution
-# Copyright (C) 2019-2020 Xavier Delaruelle
+# Copyright (C) 2019-2021 Xavier Delaruelle
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
+# the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,

script/modulecmd.in

@@ -1,11 +1,11 @@
 #!/bin/sh
 #
 # MODULECMD, execute module command corresponding to active flavor
-# Copyright (C) 2018 Xavier Delaruelle
+# Copyright (C) 2018-2021 Xavier Delaruelle
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
+# the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,

script/mpub

@@ -1,11 +1,11 @@
 #!/usr/bin/env tclsh
 #
 # MPUB, publish new release and update website
-# Copyright (C) 2020 Xavier Delaruelle
+# Copyright (C) 2020-2021 Xavier Delaruelle
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
+# the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,

script/mrel

@@ -1,11 +1,11 @@
 #!/usr/bin/env tclsh
 #
 # MREL, build release files and test them
-# Copyright (C) 2020 Xavier Delaruelle
+# Copyright (C) 2020-2021 Xavier Delaruelle
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
+# the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,

script/mt

@@ -1,11 +1,11 @@
 #!/usr/bin/env bash
 #
 # MT, run specific part of the test suite
-# Copyright (C) 2018-2020 Xavier Delaruelle
+# Copyright (C) 2018-2021 Xavier Delaruelle
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
+# the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,

script/mtreview

@@ -1,11 +1,11 @@
 #!/usr/bin/env tclsh
 #
 # MTREVIEW, review test suite log file
-# Copyright (C) 2019 Xavier Delaruelle
+# Copyright (C) 2019-2021 Xavier Delaruelle
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
+# the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,

script/nglfar2ccov

@@ -1,11 +1,11 @@
 #!/usr/bin/env tclsh
 #
 # NGLFAR2CCOV, translate Nagelfar coverage result for Codecov report
-# Copyright (C) 2017 Xavier Delaruelle
+# Copyright (C) 2017-2021 Xavier Delaruelle
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
+# the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,

script/playdemo

@@ -1,11 +1,11 @@
 #!/usr/bin/env tclsh
 #
 # PLAYDEMO, play demos recorded with asciinema
-# Copyright (C) 2019 Xavier Delaruelle
+# Copyright (C) 2019-2021 Xavier Delaruelle
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
+# the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,