Bump md-addins
[Core] Improved msbuild build host crash handling

If the msbuild host crashes, dispose the local proxy, so that the next
msbuild operation will create a new host.

Partially fixes bug #22276.
bumped md-addins
bumped md-addins
bumped md-addins
Bump to fix issues after the lib directory moved
Updated reference to md-addins
[Core] Fix project reference metadata loading bug

Properly read metadata for project references that reference other
projects. This fixes bug #22044.

In the msbuild host, only reload the project that is going to be built,
not all referenced projects.
[Mac] More path fixes after bundle structure change
Fix paths after the GateKeeper 2 migration.

Files used to be in Contents/MacOS/lib and now they're in
Contents/Resources/lib.
Fix the previous fix.

We moved *away* from MacOS to Resources, but app bundles remained in
MacOS. So we should be pointing to MacOS, and not Resources.
Merge branch 'monodevelop-5.4-branch' into monodevelop-5.5-branch

Conflicts:
	version-checks