This merges in and closes the active_particles branch, pulls in all changes up to the current tip of the enzo/enzo-dev repository, restores the FindShocksOnlyOnOutput functionality, which was unintentionally stripped out of enzo-3.0 when we switched from New_Grid_WriteGrid.C to Grid_WriteGrid.C, and adds some stability improvements to the sink active particle accretion code.
I generated a local gold standard from the current tip of enzo-dev (14ac027e4a57) and ran the answer tests against the tip of this PR (b543ec6). This passes all the answer tests in the push suite, including tests for bitwise comparisons and with strict (< 10^-13) relative tolerance.
Huge thanks to @Sam Skillman for pointing out a bad merge that was a causing a large number of test failures for an older version of this PR.
The diff is really huge since this includes more than 1000 commits, including all of the active particles work, as well as all enzo contributions since November. That makes reviewing this in detail quite difficult. I'm not sure what to do about that - if anyone has suggestions that would be really helpful.
Update: Thanks to Sam for noting that I missed a necessary include when I created this PR.