Enhance issue #97 fix. Division defaults to double division while intege...

This pull requests results in the following:
{{ 1 / 10 }} = 0.1
{{ 2 / 10 }} = 0.2
{{ 1 // 10 }} = 0

Note I have just default regular division to using doubles, while the INT_DIV operator is now used for default (including) integer division. Perhaps not ideal, but it gets us there. I'm open to criticism.