German importer: Database stuff (part 1 of many)
Small fix regarding working directories
Added sample task 'sum'
Merge branch 'ger-taskformat' of github.com:ioi-germany/cms into ger-taskformat

Conflicts:
	cmscontrib/ger-python-format/ContestConfig.py
	cmscontrib/ger-python-format/TaskConfig.py
moved some more stuff
fixed merge