(core) frameserver buffer synchronizations now flags the video pipeline as dirty

(core) fix video/feedpoll interleaving to avoid discarded updates

(platform/posix) frameserver launches now propagate themepath in env

(core) WORLDID rendertarget fixes, readbacks, attachments etc. now working correctly

(core) forceupdate on rendertarget now also processes readbacks

(core) track system page size

(core) only alter reference count on delete on object in rendertarget that is not standard output

(core) on lua proctarget, use memcpy if both scratch buffer and buffer from PBO readback are page-aligned.

(core) first outline implementation of memory interface for posix

(build) fixed regression causing LuaJIT to be excluded

(core) calctarget callback interface changed, now a userdata structure with a get(x, y, [nchannels]) metamethod is exposed.