[PATCH/RFC 0/4] gitweb: ViewVC-like "tree_blame" view

In response to Thomas Glanzmann (or rather a friend of his) request, here is series of patches which adds to tree view information about when last time and by whom was given file or directory touched. As git records "snapshot history" and commits are whole tree, and not have per file history, it means that one wants to know last commit counting from the top which has the same version of file or the same tree. This is something similar to blame (aka. annotate) for file, hence naming such view "tree_blame".

Current implementation is done inefficiently directly in gitweb, and serves rather as a proof of concept than as a serious implementation to use.

This series of patches is based on 'next' (v1.4.2-g39ee2f6) equivalent, 
but with the commit 25691fbe6d02135d55dfc3a5180e29890dce1521
   gitweb: Use --git-dir parameter instead of setting $ENV{'GIT_DIR'}
reverted, as it needs git version post v1.4.2-rc2, while I use git 
version 1.4.1.1, as there are no i386 RPMS for 1.4.2 yet.

ViewCVS/ViewVC prints the last touch of a a file in a directory and you can tell it to sort after the date criteria: http://faumachine.informatik.uni-erlangen.de/cgi-bin/viewcvs.cgi/mutt/?sortby=date#dirlist