Modify: Bomb, SpiralEmitter

- Bomb: 改為用雷射光鎖定目標，時間到爆炸，時間不到他先離開就取消攻擊。
改為使用MostBackwardEnemyDetector，鎖定最落後的敵人。
- Add MostBackwardEnemyDetector。
- SpiralEmitter: 改為每發子彈會跟著目前敵人前進。
Add EraserWeapon

- EraserWeapon:
繼承Weapon。但不使用Weapon裡面大部分的東西，包括Detector。Attack()也無用，使用自己的Collider攻擊。
Add System
Fix WeaponDetector

讓她們還沒放下就不要亂瞄準
就定位才開始瞄準
Add MirrorCrystal of LaserGun; Change many things

- Add MirrorCrystal.cs, MirrorBullet.cs
- Add to ALL Bullet prefabs(Bullet, SlowBullet, SpiralEmitterBullet,
SplittingCubeBullet) "Rigidbydy2D" (no isKinematic)
No Change
Fix Bomb Problem

Bomb can attack all enemies within or touching the BombFire now
Update to the latest system: select Weapon
Add Wave, add TankB

Changed files:
1. SystemMain
2.Enemy
3.Wave.cs
4.Tank TankB
5.WeaponDetector.cs
6.EraserWeapon Prefab
7.selectHandler
8. all weapon prefabs
9.prefabTankRed
Add Stage and Wave systems

-Add Stage and Wave systems

改動檔案：
1. StageManager
2. WaveManager
3. SystemMain
4. Wave
5. Enemy SetRoute(GameObject)
NO change
Sync before implementing SaveLoadManager
Sync before implementing SaveLoadManager
Merge branch 'testing_tang_withSystem' of https://github.com/Daeno/TowerDefence into testing_tang_withSystem
Sync Before implementing SaveLoadManager
Add SaveLoadManager
Merge with Thomas, add Win Lose

- 看gameMessanger 的update~~~ 還有GameOver
- 加一些東西 systemMain. stagemanager Saveloadmanager
- 可以merge 我成功了ㄏㄏㄏ
Small change