fix ./configure.sh to find pkg-config
Updates to build pack for Xamarin Studio (MonoDevelop 4.0)

"make packs" now builds packs for MonoDevelop 3.0 and Xamarin Studio 4.0

Bugs remain:
- Mouse-hover quick info is not working
- Alt-Enter to "send to interactive" is not working
- Types and documentation are not shown in declaration lists
More updates for Xamarin Studio 4.0
More updates for Xamarin Studio 4.0
Remove unnecesary #if
Merge pull request #99 from funnelweb/master

Updates to build pack for MonoDevelop/XamarinStudio 4.0