Moved binding resolution before invoking the root mapping
Generalised mapping, guard pattern and bottom pattern calls
Merge remote-tracking branch 'upstream/master'

Conflicts:
	plugins/org.eclipse.qvtd.xtext.qvtrelation.ui/META-INF/MANIFEST.MF
- Small fixes so that the recursive mapping call uses the correct
visitor
- Finished implementing and testing the MappingCalls.
Merge branch 'master' of https://github.com/arcanefoam/qvtMustus