!!Adding escape character to core 1.0

After we published [[Creole 1.0]] for comment, the only complaint we received was that the escape character was not in the core as mentioned by Mark Wharton and Oliver Horn.  So, we are now adding the escape character and are open for discussion until June 13.  Since it will be frozen for two years, we want to make sure 1.0 is as good as possible.