parse args inside execute()
debug: add TestDebugState
use TestDebugState to capture all git-af output for testing purposes
tests: add utility module to run aflow commands in test suite

need this for test debug mode
also, git-af run time will be measured there
gitwrapper: wrap 'git init'
gitwrapper: wrap 'git add' and 'git rm'
tests: add git repository fixture

first implementation allows to create fixture from schematic description and to bake it into actual git repo
tests: implement capturing fixture object from git repository
tests: implement fixture equality check
tests: implement fixture __str__ operator for debug purposes
debug: add profiling to debug state
tests: replace some aflow calls with git invocations for faster testing
profiling support for tests
Merge branch 'iter3/add_test_suite_v1' into iter3/optimization
EUF
gitwrapper: don't capture output for debug except if GIT_WRAPPER_DEBUG=1
gitwrapper: add grouped caches mechanism
gitwrapper: invalidate caches on git repository changes
iteration: stop using standard lru cache
gitwrapper: turn cache on explicitly(e.g from gitwrapper.cached import tag)
use gitwrapper.cached everywhere