trees and bases take damage

not finished
stationary entities

stationary entities take damage and either become unowned or dispose
Merge pull request #371 from BU-CS673/production

Production
ownables

implimented ownables now keeping track of who their owner is and
updating the network on changes

implimented for pillbox and base.

not convinced we need this functionality for tank, or mine

engineer I will update when the controller is implimented

unit tests still required
ownable

added getId() to Ownable interface
tests for ownables

all the tests for ownables
minor revision

still need get entity tile test
ownables

only changes to local ownables generate net commands
tile util

added unit test for getEntityTile()
Merge pull request #379 from BU-CS673/production

Production
fixing merge issues
conformance issues

minor revision to fit code standards
thumbs

added thumbnail images of sprites to use in user guide

can remove if they dont belong here but i wasnt sure where else to save
them
cropped a couple thumbs
Merge pull request #375 from BU-CS673/pmd-bases

Pmd bases
- Added unit tests for AStarNode, AStar and AIEngineerController
- Updated unit tests for Tank to include testing Engineer eviction
- Added Mock Engineer Creator for testing
- Fixed a bug where attempting to evict an engineer from an off-screen
  tank would cause the game to crash.
- Fixed a bug where clicking on an unreachable destination while the
  engineer was already moving would cause the game to crash.
Merge branch 'production' into Debbie

Conflicts:
	bubolo/src/bubolo/world/entity/concrete/Engineer.java
	bubolo/src/bubolo/world/entity/concrete/Tank.java
	bubolo/test/bubolo/world/entity/concrete/TankTest.java