H-uru/Plasma — pull request #320 by zrax (2013-02-25 03:42:28+00:00)
Title: Support negative substring indexes

This change makes plString::Substr's start parameter treat negative values as being from the right-hand side of the string. As an added bonus, this also defines ssize_t on MSVC, which otherwise does not define it anywhere. This definition should be compatible with Python's Py_ssize_t type, at least in Python 2.7.

This PR supersedes and closes #315