New Features

Add representation for ImageFileCollection. [#475, #515]
Added ext parameter and property to ImageFileCollection to specify the FITS
extension. [#463]
Add keywords.deleter method to ImageFileCollection. [#474]
Added glob_include and glob_exclude parameter to
ImageFileCollection. [#484]
Add bitfield_to_boolean_mask function to convert a bitfield to a
boolean mask (following the numpy conventions). [#460]
Added gain_corrected option in ccd_process so that calibration
files do not need to previously been gain corrected. [#491]
Add a new wcs_relax argument to CCDData.to_header() that is passed
through to the WCS method of the same name to allow more flexible
handing of headers with SIP distortion. [#501]
combine now accepts numpy.ndarray as the input img_list.
[#493, #503]
Added sum option in method for combime. [#500, #508]
Add norm_value argument to flat_correct that allows the normalization
of the flat frame to be manually specified. [#584, #577]

Other Changes and Additions

removed ability to set unit of CCDData to None. [#451]
deprecated summary_info property of ImageFileCollection now raises
a deprecation warning. [#486]
Logging will include the abbreviation even if the meta attribute of
the processed CCDData isn't a fits.Header. [#528]
The CCDData class and the functions fits_ccddata_reader and
fits_ccddata_writer will be imported from astropy.nddata if
astropy >= 2.0 is installed (instead of the one defined in ccdproc). [#528]
Building the documentation requires astropy >= 2.0. [#528]
When reading a CCDData from a file the WCS-related keywords are removed
from the header. [#568]
The info_file argument for ImageFileCollection is now deprecated.
[#585]

ImageFileCollection now handles Headers with duplicated keywords
(other than COMMENT and HISTORY) by ignoring all but the first. [#467]
The ccd method of ImageFileCollection will raise an
NotImplementedError in case the parameter overwrite=True or
clobber=True is used instead of silently ignoring the parameter. [#527]
The sort method of ImageFileCollection now requires an explicitly
given keys argument. [#534]
Fixed a problem with CCDData.read when the extension wasn't given and the
primary HDU contained no data but another HDU did. In that case the header
were not correctly combined. [#541]
Suppress errors during WCS creation in CCDData.read(). [#552]
The generator methods in ImageFileCollection now don't leave open file
handles in case the iterator wasn't advanced or an exception was raised
either inside the method itself or during the loop. [#553]
Allow non-string columns when filtering an ImageFileCollection with a
string value. [#567]