Crude fwd port of https://github.com/slash2009/XWMM/pull/16

It basically syncs master/frodo

If this breaks anything ill be dammed cause idk how to fix it.
Bump changelog and addon.xml

Just adding some minor changes tracking to changelog, not very detailed
but better than nothing.

Addon.xml Added provider names of ppl who have contributed to make this
happen. Not added myself because I only do janitor work.
Revert addon.xml <source>

Try to keep sources to current sources
Fix some typos and add notes.

Some glaring typos were missed, where did I put that spelkcker?

Notes:
Please follow notes, it's there because its better for everyone to work from one main copy and because it's easier to manage.