Support setting url in config

Currently we have localhost hardcoded in the service file. This patch makes it
to default to localhost, but let's people override the url in config file. Thus
changing URL doesn't need changing service file.
Let worker report real hostname

Getting rid of hardcoded 'localhost' constant and using real hostname.
Added an explanation about how to upgrade the database version schema and fixtures, both
from the developer point of view and from the sysadmin point of view.
When run without any parameter, show a help message to leave clear that it's not doing anything
Remove the deploy call that was making upgradedb.
Fix an issue with upgradedb that was making it fail when run with
--prepare_upgrade and no database instance (which shouldn't be needed,
and now isn't)
upgradedb now shows the help message if run without parameters
Remove empty spaces at the end of some lines
Filter in job list to get rid of old stuff
Tidying up the code
More cosmetic changes in the source code
Merge pull request #20 from miska/master

Support setting url in config
Redo documentation

Document how to get some instance up and running and start the other sections
of documentation as well. No more one big document, but several separate
documents.
Fixed the schema deployment in initdb (hopefully)
The deploy method was calling the overloaded method from the parent Schema
class which was breaking things since DeploymentHandler already took care
of creating tables with the call to install (not deploy). So I removed
this call to the overloaded method and renamed deploy to deploy_fixtures
to leave clear that it's a different method.
Renamed fixtures so that they're created in initdb
Moved the execute_sql_file and the initial fixture loading to the Schema class
so that just a call to deploy_fixtures deploys all of them.
Fixed a bug in job_cancel, which filtered for colums instead of columns
Fixed lots of issues related to tests:
The database was fixed so it wasn't using the one in memory for the tests,
it was loading the usual fixtures instead of the test ones,
and some other things...
update apparmor profile for git push enabled and .thumb dir
Merge pull request #28 from nilxam/update_apparmor_0411

update apparmor profile for git push enabled and .thumb dir
Merge pull request #27 from miska/master

Redo documentation
With this fix, all tests pass successfully