Following up on r1558470, only enable the sqlite errorlog in C tests when
a new --sqlite-logging argument is passed. This disables the option during
normal test runs.

* subversion/tests/svn_test_main.c
  (test_options_e): Name enum and add value.
  (cl_options): Add and document option.
  (main): Only enable logging when explicitly requested.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1560409 13f79535-47bb-0310-9956-ffa450edef68