Remove an unnecessary assert.
Allow templates to take a default set of render arguments.
Whitespace.
Merge pull request #32 from FreddieWitherden/develop

Towards v0.2.4.
Tweak the README.
Switch to using raw strings in regexps.
Simplify the Paraview writer.
Cleanups.
Cleanups.
Add support for pyramids.

Code for high-order subdivision is still required.
Add in a check for small face normals.

This can indicate the presence of degenerate elements.
Cleanups.
Cleanups.
Add support for subdividing pyramids to the ParaView writer.

Pyramids are subdivided into both smaller pyramids and tetrahedra
using an algorithm devised by Jin Seok Park.
Merge pull request #33 from FreddieWitherden/develop

Pyramids.
Improved the Developer Guide.
Merge pull request #34 from pv101/develop

Improved the Developer Guide.
Minor corrections to the developer/user guides.
RoeM flux scheme