Added params to PRIME_BB anonymous namespace

Moving towards a unified PRIME20(-like) implementation, the following
data has been added to the PRIME_BB.cpp anonymous namespace:

- _PRIME_site_type: An enum giving a key to each site type
- _PRIME_site_masses
- _PRIME_well_depths: Unbonded square well energy well depths.
- _PRIME_well_diameters: Diameters for all unbonded pairs' square well
  interaction, if there is one. The 0.75 factor for close pairs applies
  here as normal.
- _PRIME_diameters: Regular bead diameters for every pair. The normal
  0.75 factor is applied for close interactions.
- _PRIME_SC_BB_bond_lengths: SC site are held in place by three bonds to
  the corresponding residue's backbone atoms. This non-symmetric table
  gives the bond lengths here. The _PRIME_bond_tolerance applies.
- Sources for all of the values in the above variables
Merge branch 'master' of https://github.com/g-rutter/DynamO

Conflicts:
	src/dynamo/dynamo/interactions/PRIME_BB.cpp