selected. I think this is a more or less aesthetically neutral
change for the actual selection, but the selection code is reused to
draw the victory flash and that's greatly improved by not having the
tower sides remain unflashed.
[originally from svn r8843]
side: instead of locating a mouse click in whichever base grid
square contained the click location, we should check to see if a
tower protrudes on to that location from a neighbouring square. That
way, a click should reliably activate the tower that was actually
drawn under the mouse pointer.
[originally from svn r8826]
3D effect. (I only committed it without so that I could preserve a
record of how the code looked before I added it.) The 3D effect can
be disabled by setting TOWERS_2D in the environment, should anybody
seriously dislike it.
[originally from svn r8817]