Sync FSX with FSFS:  Block (record-only merge) revisions
r1603487, r1615352, r1618151, r1618641, r1618653, r1618662, r1621275,
r1621635, r1622960, r1624011, r1628762, r1629875, r1631075, r1631185
r1631239 and r1633232 from libsvn_fs_fs.

These patches concern code paths, usually backward compat & upgrade,
that don't exist in FSX.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1635817 13f79535-47bb-0310-9956-ffa450edef68
Sync FSX with FSFS:  Block (record-only merge) revisions
r1620909, r1620928, r1632776, r1632849, r1632851, r1632852, r1632853,
r1632856, r1632857, r1632868 and 1633618 from libsvn_fs_fs.

These changes convern svnfsfs functionality and need a completely
different implementation for FSX.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1635819 13f79535-47bb-0310-9956-ffa450edef68
Sync FSX with FSFS:  Block (record-only merge) revisions
r1604128, r1606564, r1606598, r1614611, r1619774, r1620912, r1627502
and r1627947 from libsvn_fs_fs.

These changes have already been replicated manually in FSX.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1635822 13f79535-47bb-0310-9956-ffa450edef68
Sync FSX with FSFS:
Merge revisions r1619358 and r1620602 from libsvn_fs_fs and resolve
the usual text conflicts with FSX.

These changes fix portability issues the the ID struct handling.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1635823 13f79535-47bb-0310-9956-ffa450edef68