Replaced 'RedundantArgumentNameIssue' with a working version.
Added code action severity levels (useful for actions handling code
errors).
Fixed bug in 'AdditionalOfTypeIssues'.
Merge pull request #301 from mono-soc-2013/luiscubal-null-analysis-using

NullValueAnalysis: Added support for using statements.
Created AddOptionalParameterToInvocationAction.
Merge pull request #302 from mono-soc-2013/luiscubal-add-optional-parameter

Created AddOptionalParameterToInvocationAction.
Fixed some formatting bugs.
Fixed some issues in 'ImplementAbstractMembersAction'.
Fixed more cases in 'ImplementAbstractMembersAction'.
Merge branch 'ArgumentName2', remote-tracking branch 'upstream/master' into ArgumentName2
Replace Redundant Check before Assignment issue with Pattern Matching
Merge pull request #303 from leoowen19/RedundantAssignment

Replace Redundant Check before Assignment issue with Pattern Matching
Cleaned up code completion bug tests.
Merged ComputeConstantValueAction & fixed it.
* RedundantCheckBeforeAssignmentIssue.cs: Synced & fixed 'new Named

* RedundantCheckBeforeAssignmentTests.cs:
* ICSharpCode.NRefactory.CSharp.Refactoring.csproj:
* RedundantCheckBeforeAssignmentIssue.cs: Synced & fixed
  'RedundantCheckBeforeAssignmentIssue'.
Added shift <--> multiply actions.
Merged pull request.
Fine tuned some hotspots for actions.
Improved hot spot for 'ComputeConstantValueAction'.
Corrected active node for multiply <--> shift actions.