Update adj walls on delete wall.
Sidemenu on the left. Handle app pause/resume.
Delete tower and wall properly.

Preventing game from rushing after unpause. Code imps.
Changed monster/shot speed functionality
Code improves
New border/spacing. Longer waves.
Upgrades take time, displayed in progress bars
spawn/exit lifted from tileGrid. tweaked progBar.
May cancel upgrades.
Selection - towers from walls. New colors