Imageio

Minor improvements related to Debian packaging.

* Standard images now have to be specified using e.g.
``imageio.imread('imageio:chelsea.png')`` to be more explicit about being
a special case and potentially involving a download.
* Improvements and fixes for the ffmpeg plugin (including improved seeking).
* Several tweaks to the tests and setup script to make it pass the Debian
build system.

This release introduces a new plugin based on Pillow, which will take care of
the "common formats" like PNG and JPEG, which was previously the role of the
FreeImage plugin. The latter is still available but the FreeImage library
is no longer distributed by default.

* New Pillow plugin to privide the common formats.
* FreeImage plugin gets lower priority w.r.t. resolving a format.
* No more automatic downloading of libraries and executable (for
FreeImage, FFMPEG and AVBIN plugins).
* Pillow plugin comes with a format to read/write animated GIF to supersede
the one provided by FreeImage.
* Various improvements/fixes to the ffmpeg plugin.
* Fixes and improvements of the DICOM plugin.
* Better support of exr images via FreeImage (by Joel Nises).
* New FEI format (for images produced by the FEI SEM microscope).

* Got rid of Lena image because it can be regarded offensive and is not (explicitly) publicly licensed.
* Fix issue with ffmpeg reader being slow on particular systems (152).
* Tiff plugin updated.
* Add Tiff resolution support (Antony Lee).
* Support for 16bit PNG's (150, by OrganicIrradiation).
* Fixes to ffmpeg plugin (149, 145, 129).
* Fix in using IMAGEIO_FREEIMAGE_LIB (141, by Radomirs Cirskis)
* Better ffmpeg verbosity and exe detection ( 138, 139, by Tim D. Smith).

* Freeimage conda package (in main channel) is updated and works on all
major OS's.
* Conda install imageio!
* Fix bug where the ffmpeg plugin fails on certain video files (131).
* Fix how dicom uses dcmtk for JPEG compressed files.

* Various improvements to the ffmpeg plugin.
* New tiffile plugin that should support most scientific formats.
* New simpleITK wrapper plugin.
* New gdal plugin.
* Freeimage plugin can load freeimage lib provided by conda.
* Dicom plugin improved handling of compressed files.
* Most plugins adopt lazy loading to keep imageio lean, fast, and scalable.
* We now build wheels for Pypi.
* Travis also tests Python 3.5.