Change size statistics

[GoogleCodeExporter]

Background:
----------
In addition to the mere fact that a certain file has changed, 
it is useful to know how much it changed. Some aggregate information
over multiple files and / or revisions may be helpful as well.

Proposed Feature:
----------------

In the "Statistics" sub-dialog of the log dialog, a new page will
* show the change size for each file and folder modified in the
  given revision range
* show the (partial) sums for each parent folder
* works on "affected paths" only (to reduce the server load)

The data may be displayed in a tree grid.

For each changed file or folder, the following information shall
be shown:

* number of "changed lines" in format "+nnn/-mmm" for non-binary files
* number of "changed props" in format "+nnn/-mmm"
* final file size and delta from initial site in format "nnXB (+/-mmXB)"

Folder nodes with property changes will be displayed as a separate
row under the name "." . Otherwise, we would need to distinguish between
local and summary information.

Implementation:
--------------

The file sizes can be retrieved using "svn info" calls and the results
may be added to the log cache size they are immutable. All other 
information can be extracted from a single unified diff.


Restrictions:
------------
Not available if more than one revision range has been selected.

Original issue reported on code.google.com by stefan.f...@gmail.com on 18 Jul 2010 at 9:17