Sync FSX with FSFS: Manually port revisions r1605444, r1606554 and r160674 from libsvn_fs_fs.
Sync FSX with FSFS:
Manually port revisions r1605444, r1606554 and r160674 from libsvn_fs_fs.

These patches switch writing revision zero from using a full template to
a generating the index sections.

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1635598 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion