Number and Dash Naming fixes

Hi all,

Added a couple of fixes which have been causing scripts to break for people:

1. Preventing mapping names and script names from beginning with a number
You will now see an error message preventing you from creating mapping names or script names with numbers at the start.

2. You're now ok to use dashes in mapping names
Dashes will now be automatically converted to underscores in the code so you're ok to use these for your names.

Thanks

John