Web interface pushed

["Clément Lassieur" <clement@lassieur.org>]

Hi Tatiana,

So, I did the pagination review and I pushed your work tonight.  :-)

I added checks to avoid crashes when the table is empty (FIRST and LAST
expect non-empty lists).

I modified a few minor things too:

- the commit message, so that it matches our convention
- the indentation
- I removed code comments, trailing '\' in SQL queries, useless
  newlines, useless exports
- I renamed a few things (e.g. thing-list with things, %pagesize with
  %page-size)
- I replaced (+ 1 x) with (1+ x)
- I used string-join to avoid long strings
- I used FIRST instead of CAR when used with LAST (for more consistency,
  but it's the exact same thing)
- I replaced FIRST and LAST with BUILD-ID and BUILD-STOPTIME, so to make
  it more furure-proof and easier to understand
- I used a format string for RESPOND-HTML (to avoid "\"\"")
- I finally opted for a non-parameter %page-size (yes, I changed my mind
  :-), I just didn't see any reason to use one)
- I removed ('page (string->number param)) from REQUEST-PARAMETERS (I
  think it was useless)
- I added a missing copyright header

And that's all!

Thanks for this work, it'll be very useful.  Don't hesitate send new
patches to improve it!

Best regards,
Clément