Merge pull request #35 from leeping/master

Fixed incorrect call to addSolvent()
Added PDBFixer to init.py
Merge pull request #37 from kyleabeauchamp/fixes

Added PDBFixer to init.py
Added applyMutations and tests.
Removed extra return value.
Remove extra print statements.
Add hydrogens afterward in examples and tests.
Give nicer error when index not found.
Initial revisions
Improved tests and docstring example.
Added more fixes.
Test number of atoms after mutation.
Test atom numbers
Test atom names in GLY and ALA after mutation.
Test atoms in LEU mutation
Merge pull request #39 from kyleabeauchamp/applymutation

Added applyMutations and tests.
Lots of improvements to appearance of UI
Merge pull request #41 from peastman/master

Lots of improvements to appearance of UI
Additional minor improvements to UI
Merge pull request #42 from peastman/master

Additional minor improvements to UI