First commit for next branch:
* new command line parser added
* topological_sorting module renamed and moved
refactoring in resolver and api for new cli
Merge pull request #17 from hadronproject/master

changes in master merged into next
Continue refactoring in resolver, api and build operation
Merge pull request #20 from hadronproject/master

changes from master branch
refactoring in build operation and related parts of lpms
refactoring in build operation, again and again
use a more proper way to handle prepare_file variable
merge safety valve fixes
Merge commit '8b2a245' into next

Conflicts:
	lpms/cli/__init__.py
refactoring in merge operation and minor changes in other parts of lpms
set internal srcdir variable if it is None
clean_temporary_directory method improved
merge_conf_fileee and configure_pending_file are relocated
merge-conf command fixed for shelve module
core, brain like module of lpms
demandimport module, borrowed from mercurial
numerous changes to comply with new parts of lpms
changes for new parts of lpms
numerous changes for better lpms