(Issue #62) Conversion behaviors don't properly clear from buildings after completion.

The error was being caused by the vagueness of the equals() method in
the Behavior class. Because equals() didn't consider assigning building,
the wrong assigned behavior could be removed from in-progress tasks.
This has been corrected.
Ovens no longer count as houses.

Ovens have been marked as houses for awhile; this is not correct and has
been fixed.
Removed _golemTexture from GolemRosterArea.

No longer needed, since GenericGolem keeps track of textures now.
New art for Foundries and Mana Pipes.

Foundries look a bit less bulky, and more "piped". Mana pipes are a bit
thicker.
Slight changes to ArchitectureEffect and GolemEffect.

Architecture stretched to display the entire building (previously part
of the building would be cut off). Golems are now slightly smaller.