graphics: MakeTiles: support layering two or more images together

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@705 d9718cc8-9f43-0410-858b-315f434eb58c
graphics: pull some traffic animation to a separate file, and use layers to compose the tiles

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@706 d9718cc8-9f43-0410-858b-315f434eb58c
graphics: more traffic animation pulled to the separate traffic.png file

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@707 d9718cc8-9f43-0410-858b-315f434eb58c
graphics: tiles.dat: allow spaces before pipes

this allows layer names to be more nicely lined up

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@708 d9718cc8-9f43-0410-858b-315f434eb58c
graphics: attempt to move wire over road to separate file

(generated tiles.png does not match previous version, so something
is wrong)

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@709 d9718cc8-9f43-0410-858b-315f434eb58c
graphics: fix road (tile 72)- dashed line in wrong position

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@710 d9718cc8-9f43-0410-858b-315f434eb58c
graphics: use layers for N/S traffic on tiles 73, 75, 78

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@711 d9718cc8-9f43-0410-858b-315f434eb58c
graphics: traffic on turns- now using layers

this fixes a couple defects in the original graphics pack-
- dashed lines on curves (tile 71) would shift or flicker during animation
- one of the road pixels (tile 70) would flash during heavy-trf animation

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@712 d9718cc8-9f43-0410-858b-315f434eb58c
graphics: traffic at squares- moved to layers

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@713 d9718cc8-9f43-0410-858b-315f434eb58c
graphics: move "MakeTiles" program into src/ directory

(but do not include it in the generated jar file)
build.xml: automatically build tiles.png from source images

It should work to just type `ant'.
The composed tiles.png will be generated in the 'build' subdirectory,
and automatically inserted into the generated Jarfile.
graphics: include RearrangeTiles.java (another utility script I wrote)
graphics: update HACKING file with new instructions for building tiles.png