increase xz memory limit
fix fseek/fsize to match definitions.
r_deluxemapping is more aggressive with regards to generating lux files on demand (but won't generate lit data at the same time).
fix webgl shader issues.
git-svn-id: https://svn.code.sf.net/p/fteqw/code/trunk@5071 fc73d0e0-1445-4013-8a0c-d673dee63da5
