On the fsx branch: Copy the remaining tests changes over from the
fsfs-format7 branch and enables FSX tests.

* build.conf
  (fs-pack-test): rename to ...
  (fs-fs-pack-test): ... this one; update file name
  (fs-x-pack-test,
   string-table-test): new test targets
  (__ALL_TESTS__): update; register new tests

* subversion/tests/cmdline/svntest/main.py
  (is_fs_type_fsx): new function

* subversion/tests/libsvn_fs_fs/fs-fs-pack-test.c
  (test_info): run this FSFS test only on FSFS tests

* subversion/tests/libsvn_fs_fs/fs-pack-test.c: rename to ...
  subversion/tests/libsvn_fs_fs/fs-fs-pack-test.c: ... this

* subversion/tests/libsvn_fs_x
  (): copy over from fsfs-format7

* subversion/tests/svn_test_fs.c
  (maybe_install_fsfs_conf): rename to ...
  (maybe_install_fs_conf): ... this; special case fsfs and fsx alike
  (svn_test__create_fs,
   svn_test__create_repos): update caller

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsx@1508077 13f79535-47bb-0310-9956-ffa450edef68