Removal of some multi-line strings

[lerno]

Currently C3 has normal "" strings, but also two kinds of multi line ones. One is a """ """ string, which also has a lot of machinery built in to allow you to set what's consumed of the indentation etc. The other is `...` raw strings, where no escape sequences are available, and doubling of ` gives you a single `.

I am planning on some compile time string functions that can help you modify the raw strings in the cases where actual escapes are desired for example.