Merge lp://staging/~julian-edwards/launchpad/buildd-manager-better-logging-bug-530040 into lp://staging/launchpad

= Summary =
improve the logging for the buildd-manager

== Proposed fix ==
https://bugs.edge.launchpad.net/bugs/530040

The logging for the buildd-manager *sucks*. It logs crap that it shouldn't
and doesn't log important stuff that it should. This branch takes care of
that!

== Pre-implementation notes ==
Chatted briefly with noodles about what to do with the logger name - in the
end a constant in the buildbase interface file appeared to be a reasonable
choice.

== Implementation details ==
Most of this stuff is changing log.debug into log.info and vice versa. I also
added the build.title to the info message when it fetches a build from the
slave, and it also now logs the files it retrieves.

== Tests ==
None exist - I really don't see the point of testing logging anyway.

== Demo and Q/A ==
I've tested this on dogfood already to make sure it logs what I need.

= Launchpad lint =

Checking for conflicts. and issues in doctests and templates.
Running jslint, xmllint, pyflakes, and pylint.
Using normal rules.

Linting changed files:
  lib/lp/buildmaster/model/builder.py
  lib/lp/buildmaster/model/buildbase.py
  lib/lp/buildmaster/master.py
  lib/lp/buildmaster/interfaces/buildbase.py
  lib/lp/buildmaster/manager.py

== Pylint notices ==

lib/lp/buildmaster/interfaces/buildbase.py
    14: [F0401] Unable to import 'lazr.enum' (No module named enum)
    15: [F0401] Unable to import 'lazr.restful.declarations' (No module named
restful)
    16: [F0401] Unable to import 'lazr.restful.fields' (No module named
restful)