Fix issue #1832: Don't use potentially locale-sensitive tests to determine if characters are in a specific subset of the ASCII subset of UTF8.
Fix issue #1832: Don't use potentially locale-sensitive tests to
determine if characters are in a specific subset of the ASCII subset
of UTF8.

Suggested by: Joe Orton <joe@light.plus.com>
(He not only reported the problem, he provided analysis to solve it.)

* subversion/libsvn_client/prop_commands.c
  (is_valid_prop_name): Test numeric values of characters directly.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion