String recognition improvements

**DO NOT MERGE RIGHT NOW**
There's some code that needs to be cleaned while we're at it.

This bring support for utf-8 strings while keeping ASCII/short-wchar support intact /yay/
Some escape codes are printed as suggested by #1051

**What's missing**
The data structures should be modified to handle non-ascii chars, the inevitable sdb-ization(, show the full string along with the disassembly ?)
Wchar endianness \o/ (everybody loves endianness)