Added curve line implementation.
Merge branch 'master' of git://github.com/qreal/qreal into feature

Conflicts:
	qrgui/umllib/edgeElement.cpp
	qrgui/umllib/edgeElement.h
git failure fixed
Fixed tabulation.
Deleted empty strings and fixed a couple of tests.
Merge pull request #861 from rustam-azimov/feature

Кривые линки