fix --list-easyblocks command line option

fix broken import in hdf5.py easyblock, and make fallback to ConfigureMake more strict
get rid of class_dumper module, integrate list_easyconfigs function into main.py

implement function renaming scheme (see issue #99)

Conflicts:
	easybuild/build.py
	easybuild/tools/class_dumper.py

add easyconfig for xorg-macros, add it as dependency for libpciaccess, add share/pkgconfig as potential PKG_CONFIG_PATH value

clarify error message when get_class fails (e.g. when --easyblock is used, see issue #234), fixed docstring