Fix up doc strings, simplify some functions, etc.
Merge pull request #288 from ketch/general_maintenance

Fix up doc strings, simplify some functions, etc.
Update apps to use new Riemann solver module names.
Merge pull request #292 from ketch/riemann_rename

Update apps to use new Riemann solver module names.

Note that this corresponds to pull clawpack/riemann#33.
Fix a few rpn_ that I missed before.
Merge pull request #293 from ketch/riemann_rename

Fix a few rpn_ that I missed before.
Remove doc directory, as it has been moved to clawpack/doc/doc/pyclaw.
Fix Riemann solver name in stegoton setplot.py.
Merge branch 'master' into riemann_shootout

* master:
  Fix Riemann solver name in stegoton setplot.py.
  Remove doc directory, as it has been moved to clawpack/doc/doc/pyclaw.
  Fix a few rpn_ that I missed before.
  Update apps to use new Riemann solver module names.
  Fix up doc strings, simplify some functions, etc.

Conflicts:
	apps/advection_1d_variable/variable_coefficient_advection.py
	apps/advection_2d_annulus/advection_annulus.py
Refactor riemann_compare to import apps.
Reorganize riemann shootout directories.