Merge pull request #314 from mono-soc-2013/luiscubal-null-analysis-fix

Null analysis fix
Merge pull request #315 from mono-soc-2013/luiscubal-null-analysis-fix

NullValueAnalysis: Implemented linq group by clause.
Disabled the null value analysis issues again (perf. issues).
Fixed 'FormatStringProblemIssue' bug.
Merged GSoc2013 MateY-IndentEngine branch from Matej Miklečić
<matej.miklecic@gmail.com> manually.
Fixed some indenter unit tests
Fixed bug in text paste indent engine.
Fixed some issues in text paste handler.
Fixed bug in TextPasteIndentEngine.
Added missing MIT X11 headers / added some failing alignment tests.
Added constructor initializer formatting.
Fixed some unit tests.
Fixed verbatim string paste bug.
Fixed paste bug.
Indent pre processor statements as default.
Fixed unit tests.
Implemented 'IndentPreprocessorStatements' option.
Renamed IndentPreprocessorStatements -> IndentPreprocessorDirectives