Ccplot

* Fixed CALIPSO plots time extent bug.

* Changed the semantics of -x command-line argument.
* Added support for time extent.

* Fixed layer products precision error.

* Fixed colormaps: calipso-cratio.cmap, calipso-dratio.cmap
and calipso-temperature.cmap.

* Interpolation method was changed from quadratic to nearest
for all products.
* Support for older versions of matplotlib (at least 0.98.1) was added.
* Layer products performance improvements (re-implementation of data
processing C).
* Fixed singular matrix bug with CloudSat profile products.
* Traceback no longer reported when trying to plot a product
that is not contained within a data file.

* Initial release.