New Rock themed music for Stage by HSR

Grid the landscape, and shortcircuit checks on the collision array if there are no nearby checked in collisions to be collided with. This is a big win for fire's ammoshove in particular. Also add a +2 that seemed missing in the check, and update fire accordingly.

Restore prior optimisation with the wildly out-of-bounds tx in LandDirty removed

Revert most of optimisation except for some obvious fixes to errors someone or other introduced. Something in the rest appears related to a crash in translation. Until I determine why or what, this stays out to not ruin people's games

merge (I'll get it next time)

sheepluva's inline patch, fix a crash in overlay

tiy new overlay graphics clean the sdlwindow created updated latest sdl fixes, corrected leaks and stuff

visual gears: fixing nemo's c-style assignment/multiplications

Store some calcs to speed up uLandGraphics a tad

partially removing DOWNSCALE ifdef -- only two remain and their removal requires dynamic allocation (btw this breaks low quality mode)

turn cReducedQuality into a LongInt and provide a series of quality flags (and best of all, this is still compatible with current frontend)

Remove hwFloat from VisualGears - they don't need the precision for syncing purposes, and it saves a whole lot of operations.

clouds: up-and-down-bouncing now without evil loop

bee: * make be correct its course only 62.5 times per second (instead of 1000) * cache values (e.g. that one for speed)

explosions: cache rounded X,Y values