ccmap

Prompted by @saraogaz in [astropy-dev mailing list asking about ccmap equivalent](https://groups.google.com/forum/#!topic/astropy-dev/7OJSXlVWBWI), I am wondering if there is already something like that in `ccdproc`. It seems to me that this would be a logical place for such a thing to exist if it does at all.

`ccmap` documentation: http://stsdas.stsci.edu/cgi-bin/gethelp.cgi?ccmap

Start by reading the linked ccmap documentation and searching the ccdproc package for existing functionality related to it. The issue does not name files, tests, or an agreed scope; done would first require determining whether an equivalent exists and defining what a ccdproc implementation should cover.

Written by the indexing model from the issue text.