#63 Multi-MODEL PDB files

[Kevin Shepherd]

The pdb specification allows multiple models in a file, usually used for
animation of NMR structures.
The openbabel library currently supports only one model per pdb file.

I will check in the tested modifications to pdbformat.cpp to allow it to handle this form, read, write and skip.

For example file, please see Request ID 1834342 in the test repository.

[Kevin Shepherd]

Logged In: YES
user_id=1900870
Originator: YES

Checked in the fix to src/formats/pdbformat.cpp as revision 2130