CText: string-based bulk inserts, events

[mweidner037]

Also push, unshift, splice.

So that users can send use strings as parameters directly instead of (...string)'s, which get immediately converted back to strings by the array serializer, wasting some CPU time.

We can also use overrides to prevent users from accidentally using non-single-character strings where characters are expected, which would cause those strings to behave as atoms. Although maybe that is sometimes desired when dealing with multi-char unicode codepoints?

[mweidner037]

Fixed by #237

I only added a few string utility methods (e.g. slice but not substring); most of the others take linear time already, so it is not a big loss to do ctext.toString().<whatever>().