add set_versionprefix, set_versionsuffix and det_installversion (static) functions to easyconfig module, and extended the easyconfig unit tests for the set functions

add support for tweaking software version and toolkit from EasyBuild command line, i.e. override whatever is specified in the easyconfig file(s) provided;
along the way, also clean up unused imports, shorten lines that are too long, fix a bug in WRF (self.wrfsubdir being empty in make_module_req_guess), and add extra functions in EasyConfig class required to support the tweaking feature

Conflicts:
	easybuild/framework/easyconfig.py
	easybuild/test/easyconfig.py

Proper way to set the logdir

Categorize easyconfig parameters

Conflicts:
	easybuild/easyblocks/c/cp2k.py

Fix missing import for get_software_root in application.py

Change test-files as well

Conflicts:
	easybuild/framework/easyconfig.py

rename EasyBlock to EasyConfig