commit d8f9b4a90a8f2caa32948bacdb6e551591facd5f
Merge: 7121b5a 5eb4992
Date:   Thu May 30 13:47:16 2019 -0400

    Fix EnergyMap::operator += (#3977)
    
    The convention for increment-and-assign type operators is to return a
    reference to the object that has just been incremented, thereby facilitating
    multiple increments in a single statement
    ```
    a += ( b+= c );
    ```
    The original author* of the EMapVector class (aka EnergyMap) did not realize
    this and so this class does not return a reference, and instead returns void.
    
    This has never been a problem for C++ code as no one has seemingly wanted
    to chain increment-and-assign operations. PyBind11, however, will take the
    returned type and assign it to the original object:
    ```
    emap1 += emap2
    ```
    is interpretted as:
    ```
    emap1 = (emap1 += emap2)
    ```
    so that this code:
    ```
    emap1 += emap2
    print("Surpise!", emap1)
    ```
    will print
    ```
    Surprise! None
    ```
    
    This PR changes the signature of just the EMapVector's operator+= and similar methods,
    but surely there are other places in the code where operators are not conforming to
    the C++ conventions.
    
    *I am the original author of this code.

commit 7121b5aa8f472b7a760bdd6435cb665448fd8e5e
Merge: 91e17db d3803ff
Date:   Thu May 30 09:55:34 2019 -0500

    Merge pull request #3972 from RosettaCommons/roccomoretti/more_pdb_loading_fixes
    
    Better categorization for PDB Diagnostic scientific tests.
    
    Add additional categories to the PDB Diganostic scientific test to knock down the number of "unknown" test failures.
    
    Mostly this isn't actually fixing any of the failures, just categorizing them better. (Though there are a few small functional changes.)

commit 91e17dbc6fd0dd53b8f61fc1cba38c6dadf696d8
Merge: 808795e da1f631
Date:   Wed May 29 18:47:39 2019 -0400

    Merge pull request #3978 from RosettaCommons/everyday847/SWM_checkpointing_hotfix
    
    Update StepWiseMonteCarlo.cc