Switch to Fourier points in FieldConvert with homogeneous expansions

This MR switches the point distribution of homogeneous expansions in FieldConvert to FourierEvenlySpaced.

The main reason for that is a performance issue recently reported when the number of Fourier modes is large. This was caused by the expansion creating a PolyEvenlySpaced distribution with many points, which scales very poorly due to the derivative matrix (for 1000 points this takes around 2 hours). This cost is also independent of the number of mpi processes...

This is also related to issue #10.

See merge request !627

Add option to use SVV only in the spectral/hp expanions

This MR adds a new option `SpectralVanishingViscositySpectralHP` that activates SVV in the spectral/hp expansion, but not in the homogeneous direction (the option `SpectralVanishingViscosityHomo1D` was already available).

The behaviour when using the option `SpectralVanishingViscosity` remains the same.

See merge request !623

Fix minor performance issue in TimeIntegration

This fixes a small mistake in TimeIntegrationScheme, which in some cases lead to a duplicate calculation (the speed up from this fix is relatively low).

See merge request !632

Fix FilterCheckpoint

This fixes a bug with parsing the `OutputFrequency` parameter of FilterCheckpoint.

I also made checkpoint 0 correspond to the initial condition, so that it is consistent with the behaviour from IO_CheckSteps.

See merge request !633

FilterHistoryPoints with 3DH1D

This MR changes how `FilterHistoryPoints` works in 3DH1D:
- The points are not required to be all in the same plane any more. When `OutputPlane` is not defined, each point is positioned in one of the planes closest to its z-coordinate. Using `OutputPlane` still forces all points to be in that plane.

- By default, the output is now in physical space (this effectively replaces !516). Writing the result in wavespace is still possible using the new option `WaveSpace`.

See merge request !621

Tidy FieldConvert output messages

This MR improves the FieldConvert output messages obtained using the `verbose` option:
- A couple of messages which were displayed twice are now fixed
- The outputs from the Process modules now follow a more consistent format, and are only issued by rank 0
- The timings of the total time taken by each module are moved to FieldConvert.cpp, using a new virtual function `GetModuleName` to display the correct information. This way timings are now automatically displayed for all modules, without having to duplicate the timer code in all modules.

See merge request !626

print an error message for erroneous equations when compiled with RELEASE



See merge request !634

Fix small bug with periodic boundary conditions

This fixes a small bug that can affect simulations with periodic boundary conditions in parallel (the conditions for triggering this bug seem extremely particular).

See merge request !631

Force fftw to use the correct compiler

This is a small change to guarantee that we use the correct compiler to build fftw.

See merge request !629

Fix missing dependency on openmpi-bin for DEB packages.

This MR fixes the missing openmpi-bin dependency, which is required for packaged executables to run (even in serial without mpirun).

See merge request !630

Small fix to make DriverAdaptive more general

This is a small fix to avoid getting an error in DriverAdaptive when there is no NekManager for GlobalLinSys.

I think it is possible that after this change DriverAdaptive will work with solvers other than IncNavierStokes (if they support variable P, of course).

See merge request !618