Re: API to get revision size on disk

I have committed an implementation in http://svn.apache.org/r1857624 , using Evgeny's new libsvn_fs ioctl API.

It is feature-complete (old and new FSFS formats, revs and revprops, packed and unpacked.

The CLI is:

    $ svnadmin rev-size /path/to/repo -r1
            1337 bytes in revision 1

plus a 'quiet' option.

There are a couple of opportunities for optimization marked in the code:
1. for the size of an unpacked rev-file, we unnecessarily read the indexes
2. for the size of packed revprops, we unnecessarily read the props

-- 
- Julian