Scons: Impove OS detection

SConstruct

@@ -1,7 +1,8 @@
 import os
 import sys
-import platform
+import platform as _platform
 env = Environment(ENV = os.environ)
+env['platform'] = _platform.system().lower();
 
 env["CC"] = os.getenv("CC") or env["CC"]
 env["CXX"] = os.getenv("CXX") or env["CXX"]
@@ -11,12 +12,16 @@ env.Append(CPPPATH = ['#src'])
 env.Append(LIBPATH = ['#src'])
 env.Append(CFLAGS = ['-g'])
 
-if platform == 'HP-UX':
+print "===================================================="
+print "Compiling Electric Fence for " + env['platform']
+print "===================================================="
+
+if env['platform'] == 'hp-ux':
   env.Append(CFLAGS = ['-Aa', '-D_HPUX_SOURCE', '-DPAGE_PROTECTION_VIOLATED_SIGNAL=SIGBUS'])
-elif platform == 'AIX':
+elif env['platform'] == 'aix':
   # COMPILE THE PROGRAMS YOU ARE DEBUGGING WITH THESE FLAGS, TOO.
   env.Append(CFLAGS = ['-bnso', '-bnodelcsect', '-bI:/lib/syscalls.exp'])
-elif platform == 'Solaris':
+elif env['platform'] == 'sunos':
   # Note the definition of PAGE_PROTECTION_VIOLATED_SIGNAL. This may vary
   # depend on what version of Sun hardware you have.
   # You'll probably have to link the program you are debugging with -Bstatic