Merged widgets editor
Shape editor calls replaced with element editor
Added icons
Fixed some grid layout segfaults
Fixed drag move highlighting redrawing
Added layout elements centering
Merge branch 'master' of github.com:qreal/qreal into widgets
Added spacers;
Moved to another namespace
Started property management system refactoring - edited main functionality
Some tool properties were moved according new usage
Old style property managers fully replaced with new ones
Removed old property managers
Added trigger tool
Merge branch 'master' of github.com:qreal/qreal into widgets
Added widgets support
Added preview
Triggers improved a bit again
Merge branch 'master' of github.com:qreal/qreal into widgets
Some docs added. Shape description moved to property
Restored ability to reopen shape in editor
Added widget editor model reopening