Closes #19

Update documentation for the ECSS definitions

Group Services and ECSS Definitions into a doxygen page

Switch order of execution to improve performance

Fix the build

This marks completion of the arbitrary type field feature

Other changes: Add a couple more tests

Other changes:
Tweaked addNewParameter() in order for the IDs to be arbitrary (insertion
of already existing ID test incoming) according to suggestion by @kongr45gpen

Additional changes:
Fixed tests for parameter setting to accommodate the new way of parameter storage

Cause was an off-by-1 error in construction of the Parameter objects.
Minor changes to documentation