httplib2 and dap removed
remove more vestiges of netcdf support
no longer needed since NetCDFFile has been removed
remove deprecated NetCDFFile
fix import
no regridding
use rita data from AOML for lic example.
remove un-needed imports
add new Line Integral Convolution (LIC) example (requires vectorplot scikit)
LogNorm: speed-up by dealing with mask explicitly