Adds a refactor that removes fairly accurate a field in all places (it is based on FindReferences).
Fixes bug 11709 part of Xamarin's bugzilla: https://bugzilla.xamarin.com/show_bug.cgi?id=11709

It makes ConvertToStaticMethod as an issue.
Fixes bug #10731

https://bugzilla.xamarin.com/show_bug.cgi?id=10731

It will look as a separate issue checker for basic interfaces and it will give the first implementation that works as base (so it will not give 5 possible conversions, even all are possible). In practice works really well. It is losely based on the ParameterCanbeDemotedIssue so I exposed the code to not duplicate it. Yet the code is much simpler this action.
Fixed description
Fixed the range of the ConvertToStaticMethodIssue
Added more unit tests to:

https://bugzilla.xamarin.com/show_bug.cgi?id=10728

There is a bug in conversion between double and float (in Convert part of the base classes)
ExpressionOfCompatibleTypeCodeIssue will not convert class types any longer.
Sample implementation for bug #11866

https://bugzilla.xamarin.com/show_bug.cgi?id=11866

The test fails because EOLN issues for now, and it works just for methods that return void for now. But it does look for methods inside the classes that have same: arguments, return type and modifiers (so are duplicates)
Merge git://github.com/icsharpcode/NRefactory
Support non void arguments
Remove unused field
index on master: 9a482c2 Remove unused field
untracked files on master: 9a482c2 Remove unused field
WIP on master: 9a482c2 Remove unused field
Code updates
Remove "Remove Field Refactory" as it is dangerous.
Merge commit '19e5dbf0ec44dd61ec6dad8bae5d6a3f1188e38e'

Conflicts:
	ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj
	ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/ConvertToStaticMethodIssueTests.cs
	ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj
Merge pull request #178 from ciplogic/master

Remove "Remove field refactory", and get fixes in other actions