Adds several macros to mark types only serializable for use within the cluster
Expanded on a comment
fix for extra space in get_all test

over-the-shoulder review by @ Tryneus
ruby driver changes, a minor fix for javascript driver, plus removing the false distinction in the drivers between int and float
Merge branch 'larkost/2912-float-rounding' of https://github.com/rethinkdb/rethinkdb into larkost/2912-float-rounding