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

Dammit. Forgot to pull/rebase before making the VG change

rope: another, small optimization