New clocktable code

[Carsten Dominik <carsten.dominik@gmail.com>]

Hi everyone,

I have just pushed a rewrite of the clocktable code.

It has more options now, and most importantly the code is
*much* cleaner.  In particular, data collection and formatting
are now clearly separated.  Anyone who would like to hack now
actually has a chance to do so in a correct way (well, Adam
Elliot succeeded anyway with the old code when he implemented
tags filtering, but that was a strike of genius....)

Here are the new properties:

      :narrow      An integer to limit the width of the headline  
column in
                   the org table.  Does not work together with `:link'.
                   If you write it like `50!', then the headline will be
                   be shortened literally, so that this will also work
                   in export and with `:link'.
      :indent      Indent each headline field according to its level.
                   This is done by a funny string like \____, but it
                   looks OK and works in export.
      :tcolumns    Number of columns to be used for times.  If this is  
smaller
                   than `:maxlevel', lower levels will be lumped into  
one column.
                   For best result, combine this with :intent t
      :level       Should a level number column be included?
      :compact     Abbreviation for `:level nil :indent t :narrow  
40! :tcolumns 1'
                   All are overwritten except if there is an explicit  
`:narrow'
      :formatter   A function to format clock data and insert it into  
the buffer.
                   Use this to make your own formatting all together.

There is a new variable `org-clock-table-defaults' where you can
specify defaults for all clocktable properties.

Since this is a rewrite, it would be very useful if a few people who
have been using clock tables in the past try this code and check if
they get the same results.

Thanks to Rainer Stengele for pushing me far enough to
finally tackle this mess and rewrite it.

- Carsten