reverting code to run in the standard way (running with overwrite as false, etc). Removing redundant code from EnvSuitPipeline.py

There are now three different functions used to download surveys from
three different server types: ODK, kobotoolbox and WRSIS. All three
functions can use past downloads if there is no connection currently, but
they have different hard-coded settings. This fix makes them
consistent and configurable with the config parameter
['Survey']['AcceptableDowntimeDays'].

import and shell script changes to use new plotting and met_extractor (now met_processing) package structures

An input argument config['Epidemiology']['Deposition']['VariableNames']
is expected as a list, so that a different variable name can be loaded
 for each listed disease. The list parsing has a bug, and is picked up
only now because the config file now provides a list of variable names.

The preparation of deposition data is quite long winded so it is moved
a standalone function.

Now that the epi model has been evaluated, parameterised, and
EWS-plotting run config have all been agreed.

And some logging messages have had their level changed.

Reflects move of untracked files to /storage/app/EWS/<region>/Resources/
for archiving there.

The second plot is changed to cover the whole simulated period, from
the start of the season to the end of the forecast period.
Epi plot titles have also been reworded.

The email config is required to set up the logging before any other
tasks are done in order to maximise coverage. It is expected that the
location of the required config file is defined in run_Processor.sh,
or exported to local environment before calling Processor.py.

The ssh commands now do not check new server identities. This prevents a
user prompt on first-time use, which otherwise inhibits Amazon Web
Server instances.