This adds NoZeroValues, a small SchemaValidateFunc that checks that a
defined value is not a zero value. It's useful for situations where you
want to keep someone from explicitly entering a zero value (ie:
literally "0", or an empty string) on a required field, and want to
catch it in the validation stage, versus during apply using GetOk.
Add the ValidateListUniqueStrings function, which is a ValidateFunc that
ensures a list has no duplicate items in it. It's useful for when a list
is needed over a set because order matters, yet the items still need to
be unique.
This adds a ValidateRegexp validation helper to check to see if a field
has a valid regular expression.
Includes test for good regexp, and test for bad regexp.
Chris Marchesi