Dealing with molecules that do not have all 3 diagonal components of the principal axis inertia tensor, i.e. point masses (mono-atomics) and linear molecules (diatomics and CO2 for example).

Adding pressure measurement via r dot f and temperature measurement and control including rotational energy.  Adding random orientation on initialisation. Modifying constantProperties construction to detect point masses. Tidy up hitWallPatch function to remove commented out stochastic wall code.

- HashTableName + StaticHashTableName continue to use debug switch
  regardless of FULLDEBUG setting

- the parameter HashTable can hold arbitrary data .. just the type of keys
  needs to match

- can use 'XX.empty()' instead of 'XX.size() == 0', 'XX.size() < 1' or
  'XX.size() <= 0' or for simpler coding.
  It also has the same number of characters as '!XX.size()' and /might/ be
  more readable

- many size checking had 'XX.size() > 0', 'XX.size() != 0', or 'XX.size() >= 1'
  when a simple 'XX.size()' suffices