fixed #840, deleting shortcut, added default size of columns
remove support mouse shortcuts
Merge pull request #921 from dima6120/hkm_bugs

fixed #840;
fixed shortcut deletons;
added default size of columns in hotkey manager page
Merge branch 'master' of github.com:qreal/qreal into subprograms

Conflicts:
	qrgui/qrgui.pro