restore $MODULEPATH after messing around with it in tests, add unit test for dealing with a very long module path
fix regex used for obtaining list of modules files from 'available --terse' output, and document it thoroughly
clean up unit tests for modules.py, make sure test with long module path runs first (required for Lmod)
list all sources used for unit tests in manifest
figure out absolute path for module command and use it, prefix modulecmd.tcl with tclsh to make it robust against older versions of modulecmd.tcl that don't have a proper hashbang
add option to tweak stdout of module command before exec'ing it, use it for modulecmd.tcl
stay under 256 chars for module path so test works with Lmod
make sure modules path is short enough for Lmod
fix Tcl environment modules support

- run 'module use' on all module paths after changing $MODULEPATH
- also set $LD_LIBRARY_PATH_modshare when (re)setting $LD_LIBRARY_PATH
- also tweak stdout for purge/use module commands
- deprecate passing of list of module paths to run_module; not used, not needed, only complicates things w.r.t. 'module use' after touching $MODULEPATH
only use 'module use' on existing paths
also tweak stdout for modulecmd.tcl unload
clean up after test_skip to avoid other tests failing on purge/use
include full output when toy module isn't there
use absolute path for test modules module path
make sure that module paths end in '/'
Revert "make sure that module paths end in '/'"

This reverts commit 60bffd4466859f7462ba3c496ceab78cab8b979f.
strip off slash ('/') at start of module names for modulecmd.tcl
implement which function for finding command paths, add a unit test and use which function for checking whether selected module command is available
rework kwargs handling in run_module function according to remarks
use lstrip to strip of '/' from start of module names