* Added model_component module to hold ModelComponent.
* Added model_component module to hold ModelComponent.

Added
=====

* New class, ModelComponent, to be a base class for landlab components.
  This is really a thin wrapper for a RasterModelGrid that contains some
  additional information about a component.


amandersillinois/landlab,Carralex/landlab,csherwood-usgs/landlab,ManuSchmi88/landlab,SiccarPoint/landlab,laijingtao/landlab,ManuSchmi88/landlab,decvalts/landlab,RondaStrauch/landlab,Carralex/landlab,amandersillinois/landlab,RondaStrauch/landlab,cmshobe/landlab,ManuSchmi88/landlab,Carralex/landlab,landlab/landlab,cmshobe/landlab,RondaStrauch/landlab,csherwood-usgs/landlab,cmshobe/landlab,decvalts/landlab,SiccarPoint/landlab,laijingtao/landlab,landlab/landlab,landlab/landlab