Update build scripts

Only for Android :(

Fix dedicated server build

Fix dll loader on dedicated server

Remove unneeded *.c files from pm_shared. (They are not built into en…

…gine). Change pm_shared headers in CMakeLists from HLSDK to engine's. Remove dead libmpg CMakeLists

mingw avi support

Partial utf-8 support

Fix mouse position on old clients in window mode

Rename xash.dll to xash_sdl.dll