MPS-20480 Action to merge non-conflicting data
MPS-20480 Non-conflicting properties/links/nodes - mergeHint attribute
MPS-20480 Non-conflicting properties/links/nodes - mergeHint attribute support
MPS-20480 Implement ours and theirs hints
add mergehint language to vcs plugin
Merge branch '3.2/mikev/mergehint'

Conflicts:
	plugins/mps-build/solutions/mpsBuild/models/build.mps
	plugins/vcs-core/core/models/diff/changes.mps
	plugins/vcs-core/core/models/diff/merge.mps
	plugins/vcs/common/models/jetbrains/mps/vcs/platform/actions.mps
	plugins/vcs/common/models/jetbrains/mps/vcs/platform/integration.mps
fix merge tests
fix errors from duplicated and self imports
GenSourcesAndCompilerXmlTest fix
return mergehints language into project and migrate it to persistence 9
Split SetMergeHint intention
Merge branch '3.2/mikev/mergehint'
GenSourcesAndCompilerXmlGenerationTest fix
Merge branch '3.2/mikev/mergehint'