Merge pull request #24 from pv101/develop

Added documentation for PyFR-Mako and Improved the User Guide.
Minor tweaks to improve GEMM performance.
Bump the version number for v0.2.2.
Merge pull request #4 from vincentlab/develop

version 0.2.2
Merge branch 'release/v0.2.2' into develop.
Whitespace.
Avoid forking once MPI has been initialised.
Unify some of the backend queue methods.
Clean up how kernels interact with queues.
Permit kernels to take keyword arguments at runtime.
Permit pointwise kernels to take arguments at runtime.
Fix an accounting bug in the RK45 stepper.
Remove the little-used DOPRI5 RK stepper.
Refactor the time-step integrators/steppers.
Make the degrees of polynomials available in the polynomial bases.
Add a matrix copy kernel to each backend.
Take advantage of Matrix.nbytes in the backend.
Permit matrices to alias other matrices.
Simplify some constructors in the backends.
Add a basic exponential solution filter.

Syntax is:

  [soln-filter]
  freq = 1
  alpha = 14
  order = 16
  cutoff = 3

where freq is how often (in terms of # of time steps) to apply
the filter; alpha sets the strength; order sets the order of the
filter and cutoff is the cutoff polynomial degree below which no
filtering is applied.