Update extdata files.
Add data files.
Update data docs.
Update for check().
Update 2001 image to 4 band landsat extract.
Update training data.
Fix case on data file.
Re-add training data to fix case.

Also update data docs.
Allow specification of class col label in extract_training_data function.
Update training data.

Class names must be valid R variable names to keep svm happy.
Fix train_grid bug and label output class image.

Also fix svm docs.
Fix example.
Fix raster and sp imports.
Re-run document.
Fix raster import warnings.

But still have R CMD CHECK note that can only be fixed if I change to using importFrom with the raster package.
Send outbands length to rasterEngine.
Require spatial.tools with layer=1 bug fixed.
Make ignoring persistence the default in chg_traj.R.
Bugfix calculation of change direction.

Previous code has the number of classes hard coded as three for producing diagonal matrix necessary for calculating the change direction.
Add stub to split classes using a cluster algorithm.

Useful for classes with high variance due to differentiation within the class - such as agricultural cover types where different crops may have different spectral characteristics.