Removed hydro_velocities from Makefile.am. Removed some more mass fluxes and code that depends on masses changing.

Removed hydro_velocities from gizmo-mfm, as the velocities need to be equal to the fluid velocity for MFM.

No unskip before rebuild

See merge request !585

Dump snapshots if the next time is strickly greater than the dump time.

Closes #447

See merge request !583

Do not unskip tasks if we already know we will have to rebuild. Minor message fixes in engine_maketasks().

Velociraptor fixes

See merge request !584

Fix output_list

See merge request !582

Use clang-format-5.0 instead of clang-format-3.8 for the code's style.

See merge request !580

Output time from a file

See merge request !560