New Feature && Code Modification

[Feature] Now BMO.Element can vanish();
BM.js
1. Implementation of vanish();
BMM.js
1. minor modifications on keydown keyup event
2. 2 new public method for dealing with BMM.elementList
Bomb.js
1. Implementation of explode() on progress;
Element.js
1. Implememntation of vanish();
wsRequestHanlder.js
1. Implementation of explode() on progress;