Temporarily increase zoom level

Color overlays.
overlays: Color/Animation overlay test images

Includes a color overlay template for as_woodentower0 and an
animation overlay template for as_lumberjack_barrack0.

All of this (including directory layout and naming conventions) is
temporary and likely to be changed later.
overlays: Color overlays for building instances

Requires fife branch `overlays`.
helios deserves all the thanks for making this possible.

Looking for `color_idle` as overlay for the action `idle`.
overlays: Animation overlays for building instances

Requires fife branch `overlays`.
helios deserves all the thanks for making this possible.

Currently only supports one overlay.
Looking for `anim_idle` as overlay for the action `idle`.