Fix bug with map key caching
Maps should support numbers as keys
Merge pull request #653 from xzyfer/feat/maps-speed-boost

Fix bug with map key caching
Merge pull request #654 from xzyfer/fix/maps-numbers-as-keys

Add support for numbers as map keys
Fix error for some selectors with interpolants
Merge pull request #655 from xzyfer/fix/issue_641

Fix error for some selectors with interpolants
Implement own isAscii since it is not present on some systems.