Improve error messages of FsiEvaluationSession
Add FSharpActivePatternGroup consisting infomation for all active pattern cases

Close #212.
Return associated getters/setters from F# properties
Implement XmlDoc and XmlDocSig for active pattern cases
Merge pull request #213 from dungpa/active-patterns

Retrieve information for all active pattern cases
Merge pull request #216 from dungpa/property-methods

Return associated getters/setters from F# properties
Merge pull request #200 from ovatsus/master

Improve error messages of FsiEvaluationSession
Added missing XmlDocSig for FSharpMemberFunctionOrValue's Events, Methods and Properties
Added catch for vref.TopValActualParent.CompilationPathOpt which some times throws exceptions
Added Entity, Field, UnionCase fixes for XmlDocSig
Added Tests for XmlDocSig
Updated ServiceDeclarations to support XmlDocSigs as raw options
Updated symbols to use refactored ServiceDeclarations
Added tests