Change format of parameter strings

This change allows dumping the parameters to a file which can then subsequently be read in from disk.
Allow using parameter module without mpi4py

The parameters.py module is used for creating parameter files for job submission scripts. For this is needs to be loaded on the login nodes, which fails if it depends on mpi4py. I removed this dependency and instead broadcast data in the driver script.
Added scripts for generating PBS scripts on ARCHER

The new directory contains a set of scripts which can be used to automatically generate jobsubmission scripts on ARCHER.