Add CC, CFLAGS, LINKFLAGS, LIBS and CPPFLAGS variables to the scons script.
Add CC, CFLAGS, LINKFLAGS, LIBS and CPPFLAGS variables to the scons script.

* SConstruct:
  (_converter,
   RawListVariable): New functions, read comma separated list from cmdline.
  (opts.AddVariables): Add new variables CC, CFLAGS, LINKFLAGS, LIBS and
      CPPFLAGS. Add this to the variables the script alreade generates per 
      platform.

krime/serf,liuzongquan/serf,Manouchehri/serf,justinweb/serf,justinweb/serf,liuzongquan/serf,Manouchehri/serf,krime/serf,liuzongquan/serf,sworda/serf,idomon/serf,blueszhangsh/serf,TommyU/serf,muthusuba/serf,justinweb/serf,TommyU/serf,wzugang/serf,muthusuba/serf,wzugang/serf,Manouchehri/serf,idomon/serf,blueszhangsh/serf,Manouchehri/serf,muthusuba/serf,justinweb/serf,TommyU/serf,krime/serf,muthusuba/serf,wzugang/serf,sworda/serf,sworda/serf,blueszhangsh/serf,liuzongquan/serf,sworda/serf,TommyU/serf,krime/serf,wzugang/serf,blueszhangsh/serf,idomon/serf,idomon/serf