Merge branch 'devel'

The devel branch has now implemented the majority of the necessary
features of HDPS and as such it makes sense to merge it into master. It
is not yet feature-complete, but it is almost there.
Add dimension sql for procedure occurrence table
Add procedure occurrence dimension with ICD-9-CM
Rename procedure occurence sql file

The original file used the ICD-9-Procedure vocabulary and this is now
reflected in the filename.
Add temporary directory

All files which are not final covariates should end up in the temporary
directory.
Bugfix: simulated outcome data now sparse

The outcomes data coming from the sql files in this project as well as
from CohortMethod are both generated as sparse files so
generatedSimulatedData() now agrees with that convention.
Refractoring of dimension functions