Use absolute paths for image locations

Makes sure the image archive and web locations
are absolute directory paths.
Add geodjango support to Measurement model

Use the geodjango objects manager in the
Measurement model. This is needed to be
able to do geographic queries through to
the point foreign key.
First commit for matchups code

First go at finding matchups between
in-situ data and images.

At the moment, it just does a search for
each image then returns the JSON results
in a list.
Constrict matchup to single measurment type

Allow user to specify a particular measurement
type to search for in the in-situ data. (Passed
though in the "parameters" field in the json
file) as with other options.
Add ordering to measurement api

Allow measurements to be ordered by point
field with all relations, so we can order
results by time
Update docs

Update the matchup code's docstrings,
and add to the documentation
Merge branch 'matchups'
Changes to logging settings

Create a new logger which will only have
warnings and above, so that the most
important messages are in one place.

Change the minimum level of the console
logger from DEBUG to INFO, to reduce the
amount of stuff being written to the screen

Put all the log files into a new separate
directory, "logs".
More robust path definitions

The bash interface scripts set some other
directory locations that are relative to
the location of the bash scripts
(TOUCAN/bash_interface), but this doesn't
work if we call the scripts from some other
path (eg when using the GUI).

Amend the scripts to explicitly retrieve
their location, so that it is independent
of where the script has been called from.
Merge remote-tracking branch 'origin/master' into pyqt_gui
path modification