rotated geodetic
Add ability to check for copyright/licence header, and fix missing headers.
Merge pull request #34 from rhattersley/header_check

Copyright/licence header checks
Pickle support for a CRS
Minor example changes.
Merge pull request #38 from pelson/small_example_changes

Minor example changes.
Rudimentary support for IGH
Merge pull request #37 from pelson/picklable_crs

Pickle support for a CRS
Added default ellipse to CRS to prevent error on systems without proj_def.dat.
Merge pull request #39 from rhattersley/igh

Rudimentary support for IGH
Added the image nest class. Tests needed.
Added substantial testing to nested image generation.
Added copyright notices.
Merge pull request #36 from pelson/img_collections

Added the image nest class for fast identification of nested images for adding to a cartopy plot.
INSTALL notes & srtm handline support.
Added more advanced srtm getter to retrieve multiple tiles in the same image.
Added untidy shaded releif example.
Small updates to the srtm code.
Updated the srtm example.
added copyright header.