Surface mesh distance filter for FieldConvert

Add a surface mesh distance process module for FieldConvert, that can used to, for example, calculate y+ values with the assistance of the wall shear stress module.

See merge request !488

MeshConvert module to extract prism-tet interface

This MR introduces a new `MeshConvert` module to extract the prismatic boundary layer, identify the interface between prismatic and tetrahedral elements and add the necessary composite to enable simulations to be performed on a sub-region of the domain.

See merge request !493

Conflicts:
	docs/user-guide/utilities/meshconvert.tex

Feature/backtrace

this appends a nice backtraceto NekError to make it more obvious where the exception was thrown. Buildbot was successful. It looks like this:

```
$ APESolver-g APE_2DChannel_WeakDG_MODIFIED.xml
/home/lackhove/code/_build/nektar/solvers/APESolver/APESolver-g() [0x482d7d]
/home/lackhove/code/_build/nektar/solvers/APESolver/APESolver-g() [0x48346f]
/home/lackhove/code/_build/nektar/solvers/APESolver/APESolver-g(_ZN6Nektar5ArrayINS_4OneDENS0_IS1_dEEEixEj+0x124) [0x48bc92]
/home/lackhove/code/_build/nektar/solvers/APESolver/APESolver-g(_ZN6Nektar3APE12v_InitObjectEv+0x67d) [0x483d79]
/home/lackhove/code/_build/nektar/solvers/APESolver/APESolver-g(_ZN6Nektar11SolverUtils14EquationSystem10InitObjectEv+0x23) [0x48a595]
/home/lackhove/code/_build/nektar/solvers/APESolver/APESolver-g(_ZN6Nektar3APE6createERKN5boost10shared_ptrINS_12LibUtilities13SessionReaderEEE+0x5a) [0x48a77a]
/home/lackhove/code/_build/nektar/library/SolverUtils/libSolverUtils-g.so.4.1.0(_ZN6Nektar12LibUtilities10NekFactoryISsNS_11SolverUtils14EquationSystemERKN5boost10shared_ptrINS0_13SessionReaderEEENS0_4noneESA_SA_SA_E14CreateInstanceESsS9_+0xe2) [0x7f81c9935c46]
/home/lackhove/code/_build/nektar/library/SolverUtils/libSolverUtils-g.so.4.1.0(_ZN6Nektar11SolverUtils6Driver12v_InitObjectERSo+0x536) [0x7f81c9931428]
/home/lackhove/code/_build/nektar/library/SolverUtils/libSolverUtils-g.so.4.1.0(_ZN6Nektar11SolverUtils14DriverStandard12v_InitObjectERSo+0x23) [0x7f81c9948acb]
/home/lackhove/code/_build/nektar/library/SolverUtils/libSolverUtils-g.so.4.1.0(_ZN6Nektar11SolverUtils6Driver10InitObjectERSo+0x2e) [0x7f81c9946a64]
/home/lackhove/code/_build/nektar/library/SolverUtils/libSolverUtils-g.so.4.1.0(_ZN6Nektar11SolverUtils14DriverStandard6createERKN5boost10shared_ptrINS_12LibUtilities13SessionReaderEEE+0x64) [0x7f81c994aba2]
/home/lackhove/code/_build/nektar/solvers/APESolver/APESolver-g(_ZN6Nektar12LibUtilities10NekFactoryISsNS_11SolverUtils6DriverERKN5boost10shared_ptrINS0_13SessionReaderEEENS0_4noneESA_SA_SA_E14CreateInstanceESsS9_+0xe2) [0x479e24]
/home/lackhove/code/_build/nektar/solvers/APESolver/APESolver-g(main+0x14a) [0x470582]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f81c2beab05]
/home/lackhove/code/_build/nektar/solvers/APESolver/APESolver-g() [0x46f779]

Fatal   : Level 1 assertion violation
Where   : /home/lackhove/code/nektar/library/LibUtilities/BasicUtils/SharedArray.hpp[552]
Message : Element 4 requested in an array of size 4
```

See merge request !495

Added missing packages for the Collections library.

This MR adds the missing packages for the Collections library. Also adds the PulseWaveSolver package to the main Nektar++ metapackage.

See merge request !505

Feature/filter expressions

This MR updates the filters to support the use of expressions in numeric parameters. For example, one can define the output frequency of a filter as 1/TimeStep so that outputs are produced at consistent time intervals irrespective of timestep.

This MR also tidies up some of the filter code, improves code consistency, namespace consistency, removes namespace indentation, etc.

See merge request !489

PtsField: Use nektars geom tolerance for finding exact matches during shepard in…

Use nektars geom tolerance for finding exact matches during shepard interpolation and check weigts for NaN after computation

This fixes a problem where the weights become inf if the points are too close.

Buildbot is all green

See merge request !499