Replace C++ license headers referring to `fifengine.de` with `.net`

One more time.
Replace python license headers referring to `fifengine.de` with `.net`

Also caught some bash in the process apparently.
Merge pull request #774 from fifengine/fifengine-net

Replace license headers referring to `fifengine.de` with `.net`
Fixing various links
Removing guichan from ext

This includes removing the ext option from scons.  fixes #771
Merge branch 'master' into triggers