Include all potential build targets when cleaning, so scons will remove all targets.
Include all potential build targets when cleaning, so scons will
remove all targets.

* SConstruct:
  (): reset the Default when cleaning to include all targets

lazysoez/serf,zhupan/serf,SirJson/serf,lazysoez/serf,SirJson/serf,pengdu/serf,stoneCC/serf,alex1818/serf,lazysoez/serf,zhengcq315/serf,stoneCC/serf,yesoce/serf,KyleSanderson/serf,stoneCC/serf,zhengcq315/serf,KyleSanderson/serf,x-clone/serf,alex1818/serf,stoneCC/serf,KyleSanderson/serf,soufianeEL/serf,google-code-export/serf,SirJson/serf,alex1818/serf,x-clone/serf,google-code-export/serf,zhupan/serf,soufianeEL/serf,yesoce/serf,zhengcq315/serf,alex1818/serf,yesoce/serf,zhupan/serf,pengdu/serf,google-code-export/serf,yesoce/serf,zhupan/serf,x-clone/serf,SirJson/serf,x-clone/serf,soufianeEL/serf,pengdu/serf,pengdu/serf,soufianeEL/serf,KyleSanderson/serf,google-code-export/serf,zhengcq315/serf,lazysoez/serf