Alternate 2D Textures for qormas
manually edited bgfs to include a texture name, added a ground snow
texture
renamed textures to be below grd65535.bgf
Added Qormas Gifts
Rename roomanim.c SectorChange to SectorAnimate.

This is a function called by HandleSectorAnimate in server.c, which is
called by the BP_SECTOR_ANIMATE protocol, which is unused by the (old)
client at the moment. Going to make a proper SectorChange
protocol/function so giving the old one a more appropriate name.
New protocol BP_SECTOR_CHANGE to change sector flags.

Calls HandleSectorChange in server.c which calls SectorChange in
roomanim.c and this function can set new values for the sector's depth
and scrolling speed. Rooms keep track of this using
plSector_flag_changes. SetSectorFlags changes the flags and
RemoveSectorFlagChange removes the changes (in room.kod).
Add a way to prevent either variable from being changed.
Implement rain and snow in software renderer.

Also included some declarations for the hardware renderer part.
Implement rain in hardware renderer.
Implement snow in hardware renderer.

Also raised the emitter height for rain and snow, to make it look more
realistic.
Server infrastructure for snow/rain.

Qormas will now also activate snow in all rooms by default.
Add preferences menu option to turn weather off.

In both English and German clients.
Add small amount of x velocity to snow.

Recommendation from Keen.
Rain/snow refactor, particle effect bugfix, CV window transparency.

Refactored the code for rain/snow and made a lot of adjustments.
Fixed a bug that was preventing random particle position from being
truly random.
Made the windows in CV main room properly transparent so weather effects
happening outside can be seen.
Handle effect changes correctly.
Add msg to remove a changed texture.
Add wreath texture and snow changing code to Qormas.

Qormas now changes the texture on doors (to add textures with wreaths)
and also calls StartSnow in room.kod if necessary which handles snow for
that room. EndSnow removes it.
Add sector/sidedef IDs for placing xmas decorations.

ID 15 is for sidedefs that require a snow texture, Sector ID 10 is for
water which doesn't get snow, IDs 21-34 are for door texture changes.
Add water effects and ice texture.

Use the new protocol to change water into ice (no scrolling, no depth).
Added a new ice texture to place on the water.
Fix sector IDs