Added new action ChangeAccessModifierAction.
ChangeAccessModifierAction: Fixed bug that prevented action from being run on private accessors.
Fixed bug in ChangeAccessModifierActions: Action offered to modify accessors in virtual properties.
Merge branch 'luiscubal-access-modifier-actions' of https://github.com/mono-soc-2013/NRefactory into luiscubal-access-modifier-actions
ChangeAccessModifierAction now allows changing the modifier of virtual/override/new members. Since the action can cause compile errors anyway, there's no point in disabling it in this case.
Made ChangeAccessModifierAction less intrusive (use Script.ChangeModifier).
Fixed issue involving method type parameter constraints
Merge pull request #268 from erik-kallen/generic-method-type-parameter-constraints

Fixed issue involving method type parameter constraints
Fixed some issue crashes.
Merge branch 'luiscubal-access-modifier-actions' of github.com:mono-soc-2013/NRefactory into mono-soc-2013-luiscubal-access-modifier-actions

Conflicts:
	ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj
	ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj
Fixed project file.
Turn off the msbuild engine.
ChangeAccessModifier should only work on entity name & entity
modifiers.
Fixed bug in 'ChangeAccessModifierAction'.
Added 'AbstractAndVirtualConversionAction'.
Fixed bug in 'NegativeRelationalExpressionIssue'.
Removed test results files.
ChangeAccessModifierAction has now the right location.
Fixed some issues with 'AbstractAndVirtualConversionAction'.
ChangeAccessModifierAction is now more picky about the nodes on which
it pops up.
Fixed issue in 'AbstractAndVirtualConversionAction'.