Attach to process - reimplementing some old work done by "Tak" a couple years back.
Merge remote-tracking branch 'upstream/UnitySoftDebugger' into UnitySoftDebugger

Conflicts:
	main/src/addins/MonoDevelop.Debugger/MonoDevelop.Debugger/AttachToProcessDialog.cs
	main/src/addins/MonoDevelop.Debugger/MonoDevelop.Debugger/Extensions.cs