bulldozer: fix adjacent roads/wires/etc. when bulldozing

This patch restores the correct bulldozer behavior regarding adjacent
roads, wires, and rails that was lost when the toolstroke series
of patches were applied.

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@768 d9718cc8-9f43-0410-858b-315f434eb58c
zoom-levels: fix to recognize the numpad "-" key to zoom out

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@769 d9718cc8-9f43-0410-858b-315f434eb58c
keyboard: add shortcut keys to Game menu
keyboard: define access keys for more menus
zoom-levels: add menu options for Zoom In and Zoom Out