Fix issue #121: scons CFLAGS doesn't accept more than one flag.
Fix issue #121: scons CFLAGS doesn't accept more than one flag.

* SConstruct: Make CFLAGS, LIBS, LINKFLAGS and CPPFLAGS take a space-separated 
      list so that flags like "-Wl,-foo,fooval" can be specified.

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