include ais conversion

extra_script.py

@@ -1,10 +1,17 @@
 print("running extra...")
 import gzip
 import shutil
+import os
 FILES=['web/index.html']
 
 def compressFile(inFile):
     outfile=inFile+".gz"
+    if os.path.exists(outfile):
+        otime=os.path.getmtime(outfile)
+        itime=os.path.getmtime(inFile)
+        if (otime >= itime):
+            print("%s is newer then %s, no need to recreate"%(outfile,inFile))
+            return
     with open(inFile, 'rb') as f_in:
         with gzip.open(outfile, 'wb') as f_out:
             shutil.copyfileobj(f_in, f_out)