First steps in optimizer.

Still WIP, though, but it already optimizes e.g. this:

default { timer() { 2+2; } }

to this:

default { timer() { 4; } }

main.py

@@ -2,17 +2,25 @@
 
 from lslopt.lslparse import parser,EParse
 from lslopt.lsloutput import outscript
+from lslopt.lsloptimizer import optimizer
 import sys
 
 def main():
     if len(sys.argv) > 1:
         p = parser()
         try:
-            symtab = p.parsefile(sys.argv[1])
+            p.parsefile(sys.argv[1])
+            funcs = p.functions
+            symtab = p.symtab
         except EParse as e:
             print e.message
             return 1
         del p
+
+        opt = optimizer()
+        opt.optimize(symtab, funcs)
+        del opt
+
         outs = outscript()
         script = outs.output(symtab)
         del outs