Added add_attribute method to ClawData and some notes on things to do.
add new data attributes
Add check richardson parameter
Correct plots target
fix to paths in imagediff
Merge remote-tracking branch 'upstream/master' into rjl

* upstream/master:
  Correct .* rules
  Add removal of module files when clobbering or newing
  Minor fixes to clone function
  Path change for runclaw
  Combine git functions, add command line interface
  Move source for git-clone to git module
  Move all source into clawutil pacakge
  Add preprocessor flags
  Add clawapps repository support, fix missing error
  Final bug fix for shell type option
  Bug fix to newly added options
  Add shell type output option
Remove momentum_refinement flag and change data name
Add path creation functions to runclaw
Modified imagediff.py to add a --relocatable option.

This option copies figures from dir1 and dir2 to subdirectories of dir3 so the latter can be moved to a webpage for sharing with others.
Merge remote-tracking branch 'upstream/master' into rjl

* upstream/master:
  now compatible with pip install develop
  more correct format for setting up eggs
  setup.py file for clawutil
Rewriting clawdata.py, with bugs

Want to redesign data_write function.
New clawdata.py writing output file for amrclaw example
New input params works on example1
Modified verbose output in chardiff
Fixes to clawdata.py for new inputs
Changed some macro names in Makefile.common
Fixed messages printed by runclaw.py
Minor tweaks for move to new repos
Merge branch 'mutlilayer-geoclaw' into multilayer
Merge branch 'master' into multilayer