Sync FSX with FSFS:
Merge and adapt revisions r1531982 and r1604717 from libsvn_fs_fs.
Various conflicts were caused by reordered code and renamed functions
in FSX.  Lots of additonal code / callers to be adapted.

This ports the revision_file_t abstraction to FSX.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1635317 13f79535-47bb-0310-9956-ffa450edef68
Follow-up to r1635317: Fix build.

* subversion/libsvn_fs_x/rev_file.h
  (svn_fs_x__init_revision_file): Remove this unused and conflicting
                                  declaration.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1635318 13f79535-47bb-0310-9956-ffa450edef68