Supports a colony_tolstring function for transforming values.
Fixes regex string conversion.
Reports errors as cast strings.
Adds error log when lua state cannot be instantiated.
Corrects regex flags to be booleans from C API.
Removes ellipses characters from colony-js.lua
Fixes nil comparisons with tables.
Fixes colony_isarray to respect boolean returned from Lua fn.
Merge #586 r=@kevinmehall: Adds fixes from colony-luajit branch.

These are all the fixes from the luajit branch that don't involve changing interpreters. These changes work on master, but are also blockers for proper operation under luajit (for various strictness and minor API differences).