Backport fix for issue #4340, "fs layer should reject filenames with
trailing \n", to the 1.7.x-issue4340 branch.

Merge r1461562 and r1461580 from trunk, resolving a text conflict
with the former revision, and a tree conflict with the latter revision.

* subversion/libsvn_fs/editor.c: This file doesn't exist in 1.7.x,
   so this change on trunk doesn't apply.

* subversion/libsvn_fs/fs-loader.c: Fix a text conflict caused by the
   existence of additional new tests in trunk. Tweak the test to not
   rely on SVN_TEST_ASSERT_ERROR which doesn't exist in 1.7.x.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.7.x-issue4340@1461592 13f79535-47bb-0310-9956-ffa450edef68