Fix module sub-command abbreviation match to ensure passed abbreviated
form fully match sub-command, not only its minimal abbreviated form. As
an example, ``lod`` or ``loda`` do not match anymore the ``load``
sub-command, ``lo`` or ``loa`` still do.
Adapt test* procedure to call test for each supported shell when
test_shell argument is set to 'ALL'.
Transform all tests set for all shells with a common output to use this
new 'ALL' test_shell argument.
Pass 'OK' or 'ERR' string to test procedure, then these procedures will
use the new internal 'shell_ok' and 'shell_err' procedures to translate
these bare OK/ERR strings in the appropriate code for the given shell.
Make module command handling appear in a single location, the module
procedure, rather than having a duplication of code in the main section.
This modification simplifies the addition of new commands or the
adaptation of existing commands as everything has to be done only once.
Now calling module from a modulefile or a modulerc benefits from the
same command shortcuts than when it is called from the command line.
Moreover do not print anymore the module usage message when an invalid
command is typed, as this large message often hide the error printed on
the first line. An advice to type "module --help" is printed instead.
