tiles.rc: annotate tiles that can be bulldozed

these tiles can be bulldozed clean using the bulldozer

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@893 d9718cc8-9f43-0410-858b-315f434eb58c
tiles.rc: eliminate BULLBIT and use annotation instead

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@894 d9718cc8-9f43-0410-858b-315f434eb58c
tiles.rc: synthesize BULLBIT when saving file

this allows files to correctly load in older versions of Micropolis

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@895 d9718cc8-9f43-0410-858b-315f434eb58c
tiles.rc: re-allow bulldozing dead zones

That is, we allow tiles that belong to zones whose center tile has been destroyed
(e.g. from a fire) to be individually bulldozed. This used to be allowed by setting
the BULLBIT on those tiles when the center tile is destroyed (see killZone() method)
but now that we no longer use BULLBIT, we need to test whether the center tile still
exists when deciding if a tile can be bulldozed.

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@896 d9718cc8-9f43-0410-858b-315f434eb58c
api: getTile() now returns masked tile number

use getTileRaw() to get the raw tile number

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@897 d9718cc8-9f43-0410-858b-315f434eb58c
api: use masked tile number for tile-check methods

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@898 d9718cc8-9f43-0410-858b-315f434eb58c
api: TileConstants- never accept "raw" tile numbers

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@899 d9718cc8-9f43-0410-858b-315f434eb58c
cleanup: no longer need to apply LOMASK

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@900 d9718cc8-9f43-0410-858b-315f434eb58c
cleanup: use getTile() instead of direct access where possible

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@901 d9718cc8-9f43-0410-858b-315f434eb58c