[NUnit] Use Nuget reference in project template
[NUnit] Update NUnit runner to 2.6.3

And reference it via NuGet
[Core] Default to .NET 4.5 for new projects
Fix issue with the same file being open twice.

If you have a file A open and then open a solution where file A is in
the user preferences, then file A will be opened twice.
Merge pull request #626 from lukaszunity/upstreaming/same-file-opened-twice

Fix issue with the same file being open twice.
[Nunit] Add missing nuget restore
[NRefactory] Try to prevent infinite loop in type lookup.

Unfortunately I can't reproduce it - but I have a stack trace that shows it can happen.
Bump nrefactory.
[IDE/XML] Bug 20468 - XML Format document removes all undo history
Merge pull request #628 from DavidKarlas/xmlFormat

[IDE/XML] Bug 20468 - XML Format document removes all undo history
Hide the dockbars while we're displaying an overlay, because otherwise
there are issues with mouse clicks being eaten by the dockbars. For
example, when the welcome page is up the dockbar on the right eats
clicks when the user tries to grab the right scrollbar.

Fixes https://bugzilla.xamarin.com/show_bug.cgi?id=19445
Fixed 'Bug 21980 - Can't copy text from Test Results pad'.
[TypeSystemService] Check for serializable flag before adding files to
a project content.
The check was missing there.
[Ide] Connect references for non .NET projects automatically.
Was requested for the D language binding. Doesn't affect C#.
Merge branch 'master' into ios8