Summary:
Warn if field alias contains illegal characters
Detailed Description:
Would be great if FormBuilder could warn/reject field aliases with illegal
characters. Currently it allows them and then just fails to handle the
submission for those fields, and it's only when you start trial-and-error
debugging that you find out it's an alias name issue.
The character that usually trips me up is hyphen - some modules allow a hyphen
in an alias and some do not.