refactored modules.py, required to fully support alternative module naming schemes (note: break modules.py API!)
- flesh out hardcoded assumption that module names are of format '<name>/<version>'
- redefine function signature of available/exists/show/dependencies_for/modulefile_path functions: only accept module name parameter, not name and version parameters
- return list of modules as list of strings instead of list of (name, version) tuples
- get rid of (unused) modulePath/mod_paths named arguments in available/exists functions
- stop using $_LMFILES_ as fallback for $LOADEDMODULES (latter should always work, we can't isolate module name from full path with making assumptions about depth)
- add module_software_name function to determine software name from module file
- hoist code common between module_software_name/modulefile_path functions into get_value_from_modulefile function
- add unit tests for available/exists functions
- fix running options unit tests stand-alone