Added block placement handling for several blocks (see #119).

Placement handling for dispensers, droppers, levers, furnaces, and
hoppers. Right-click (toggle) handling for levers.
Merge branch 'master' of https://github.com/SpaceManiac/Glowstone into SpaceManiac-master

Conflicts:
	src/main/java/net/glowstone/entity/GlowEntity.java
git push origin masterMerge branch 'SpaceManiac-master'