Update Julia.tmLanguage

-Fixed function definitions to handle optional parametric bracket recognition
-Added '$' as interpolation operator
-Added 'e' and 'pi' as numeric constants
-Added 'true' 'false' 'nothing' as language constants
-Added basic Bitstypes
-Fixed Type assertions to handle parametric types (though this is still a little messed up with Unions...)
Merge pull request #2460 from karbarcca/patch-1

Update Julia.tmLanguage