updates to escape/unescape with tests
re-implement escape/unescape; add tests
correct encodeURI/decodeURI and test
optimize decodeURI
correct encodeURIComponent/decodeURIComponent and test
tests for regex
implement array.map and array.filter
cast result of `%` to float
fix: divide by zero should not throw
codegen: optimize cases where we don't need to call to_number()
update browserify
update readme