refactored code to omit F# 3.1 features (this will allow compilation in Xamarin Studio)
Revert "refactored code to omit F# 3.1 features (this will allow compilation in Xamarin Studio)"

This reverts commit c6b02b2ca31ba85803501d3fe8d08282cbf0db9d.
Merge branch 'master' into develop
Improved Polling WRT UoM-demarcated timeouts and calling from other CLR languages
undoing previous commit's uint64 nonsense
add new perf test for comparison with NetMQ
replaced Timing module with appropriate BCL calls
add tryPollInput,TryGetInput to simplfy common polling scenarios
Updated tests to minimally exercise new polling functions
updated docs to reflect removal of Timing module
added updated samples for chapter 1 of zguide
updated to latest version of FSharp.Formatting
improved documentation
improved intro tutorial
updated libzmq to 4.0.5
changed pollIO compiled name to PollIO; updated version test; hid Text property on Version
more zguide examples
fixed potential memory leak in Message.tryRecv; added more zguide examples
Merge branch 'develop'