Do not check characters while settings deserialization from xml.

There is no verification that settings can not contain invalid xml characters.
Closes #2450.
Support removing old "&GitExt" menu
Old git menu removing fixed
Support changed path to DiffMerge. Closes #2454
Ignore COM exceptions in UpdateJumplist. Closes #2269
Pushing HEAD fixed. Closes #2165
Merge remote-tracking branch 'origin/release/2.48' into release/2.48

Conflicts:
	GitExtensionsTest