Merge branch 'release/v0.2.0' into develop.
 Added .ini file documentation to the User Guide
Corrections to the User Guide documentation
Corrected docs for prismatic elements
Corrections to the User Guide documentation
Merge pull request #15 from pv101/develop

 Added .ini file documentation to the User Guide.
Merge pull request #17 from FreddieWitherden/develop

Add in support for anti-aliasing.
Fix warnings in the documentation.
Minor syntactic and stylistic corrections.
Add riemann-invariant bcs (Jameson & Baker, 83-1929, AIAA)
Merge pull request #19 from GeorgeDemos/develop

Add Riemann-invariant, characteristic boundary conditions.
Whitespace.
Bump the version number for v0.2.1.
Fix a bug introduced in the previous commit.
Merge branch 'release/v0.2.1' into develop.
Switch to locally importing mpi4py.

This avoids potentially unwanted calls to MPI_Init() when
importing PyFR modules.