remove some dead code from Gruntfile, improve Rule.symlink*
remove some dead code from Gruntfile, improve Rule.symlink*

jpevarnek/uproxy,IveWong/uproxy,itplanes/uproxy,roceys/uproxy,MinFu/uproxy,MinFu/uproxy,jpevarnek/uproxy,dhkong88/uproxy,itplanes/uproxy,itplanes/uproxy,uProxy/uproxy,chinarustin/uproxy,qida/uproxy,dhkong88/uproxy,MinFu/uproxy,chinarustin/uproxy,chinarustin/uproxy,uProxy/uproxy,roceys/uproxy,qida/uproxy,uProxy/uproxy,IveWong/uproxy,chinarustin/uproxy,jpevarnek/uproxy,qida/uproxy,dhkong88/uproxy,itplanes/uproxy,dhkong88/uproxy,jpevarnek/uproxy,roceys/uproxy,roceys/uproxy,IveWong/uproxy,qida/uproxy,MinFu/uproxy,uProxy/uproxy,uProxy/uproxy,dhkong88/uproxy,itplanes/uproxy,IveWong/uproxy,chinarustin/uproxy,roceys/uproxy,MinFu/uproxy,qida/uproxy,jpevarnek/uproxy