GitLab

Speed up a slow test case by using a smaller topology file

Commented out testEinsteinCrystal(), since it failed much too often

Fixed some test failures

Fixed a rare memory corruption error when roundoff causes tile indices to be wrong

Fix error in setting up AMOEBA systems when useDispersionCorrection is specified (retry)

Removed 'void' declarations from getCutoff/getCutoffDistance methods so that swigInputBuilder.py would correctly wrap return values.

Fix Clang warning about unhandled enum values.

In travis, use multiple cores.

Travis VM's have up through 2 cores. Passing a -j2 flag should make/ctest the builds/tests faster.

Clang had been generating the following warning:

```
ParsedExpression.cpp:123:13:
warning:
      30 enumeration values not handled in switch: 'CONSTANT', 'VARIABLE',
      'CUSTOM'...
            [-Wswitch]
                switch (node.getOperation().getId()) {
                                ^
                                1 warning generated.
```

To get rid of this warning, I added a default case, which does nothing.

XmlSerializer generates XML directly rather than going through TinyXml

Fix residue assignment in PSF parser

(which means that consecutive residues may have the same residue number _and_
name, but are different residues).

GromacsTopFile adds exclusions based on [ exclusions ] directives

Force field XML files can specify CustomNonbondedForces

Added documentation for using a CustomNonbondedForce in force fields.  Also updated documentation on how to specify a tabulated function.

Add virtual sites

Improve unit handling in charmm crd file classes.