Plenopticam

The 0.1.3 release contains the following new features:
- prevention of image artifact in saturation for clipped pixels in Lytro Illum images
- option for contrast automation
- export thumbnail image in output folder
- log file export for error reports
- Linux support (App bundle and OS-specific fixes)
- command line features (e.g. processing a folder of light-field images)
- fix for issue2 opened by hongyann
- general bug fixes for more stability

This beta release contains a series of minor fixes for better stability including:

* more generic row and column estimation of centroid array
* unit tests using the OpEx dataset

This beta release contains several fixes that improve stability including:

- fix export path for extraction of refocused images
- use distinctive file-naming for sub-pixel precise shift and integration
- freeze background window when *browse* buttons are pressed (prevents from opening too many windows at once)
- introduce quick color balancing treatment for saturated pixel channels

This is the first release of the light field rendering software meant for test purposes.