Alter command loop to handle project (preliminary)

1. Remove Script command
2. Add Project command
3. Parse and DoCompletion take filenames as an extra argument
3. Change loop state to include project
4. Add option (for compiler service) construction on demand using
   code similar to that from the monodevelop binding
5. Temporarily disable ToolTip command
Allow Otherflags to be empty
Fix crash caused by compiling against wrong DLLs

Was using version 2 of Build.{Tasks,Utilities}
Ensure that HintPath resolution can succeed