change --amend command line option, so it can be used multiple times and a list of provided values is being constructed

start working on getting generate_ec_file to support both selecting and generating of easyconfigs;
add (very) preliminary support for --amend, as suggested by @fgeorgatos

complete support for generating an easyconfig file according to the desired specifications, using an available easyconfig as base; one problem is that 'tweaking' the EasyConfig instance w.r.t. verions and such is not sufficient; for example, when the software version is changed, also sources and possibly dependencies, patches, ... need to be tweaked

preliminary support for generating easyconfig file according to given requirements and for dumping an EasyConfig instance to file (only name and version, for now)

split up new stuff into functions;
start implementing find_best_matching_easyconfigs to find candidate easyconfigs to use

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