Tidied up solution file to remove unwanted platforms
Add SortByKey(), GroupByKey() to FunctionObject.ds
Add FilterOut() to FunctionObject.ds
Add SortByComparision()
Add Reduce()
Merge pull request #1142 from junmendoza/DSDynamo_ParserWork

Full syntax support for Longest replication guide postfix
Merge pull request #1141 from ke-yu/ChocoButter-2Become1

Add some functions to FunctionObject.ds