K2fov

- Increase padding to 35px as a mitigation for the fact that the final C14 and C15 fields will rotate by 0.365 degrees to account for the low-gain antenna change.
- Configures the final field for C12, which incorporates the required 0.365 degrees roll change (KSO-471).

Module 4, one of Kepler's 21 CCD Modules, retired on July 20, 2016. K2fov v5.1 was released to incorporate the loss of this module. Targets falling on this module, i.e. targets falling on channels 9, 10, 11, or 12, are no longer considered to be "on silicon" as of this version.

More details: http://keplerscience.arc.nasa.gov/retirement-of-ccd-module-4-confirmed.html

- This is the first release to contain the final coordinates for Campaigns 14, 15, and 16 (K2 GO Cycle 5).

This release adds the following features:
- `K2findCampaigns` and `K2findCampaigns-byname` now print the predicted (channel, col, row) of targets that fall on silicon, thus providing a handy (ra,dec) => (channel,col,row) conversion tool.
- The padding was increased to 6px in response to our improved understanding of the magnitude of the optical distortions which are not accounted for by K2fov [15].
- The `c9.pixelInMicrolensRegion()` function is now aware of the masks to cover ongoing microlensing events that were added shortly before the start of the first half of Campaign 9 (C9a).

This release updates the C9 microlensing superstamp definition to the final version (v5).

It also fixes three small annoyances:
- fixes the `No handlers could be found for logger "K2fov"` warning message seen on older version of Python; [2031866dfb4375f3d4bdc029d3577997300d9d41]
- suppress the `FutureWarning` message occasionally raised by old versions of matplotlib; [14]
- enable K2fov to run on a headless machine; [f357c21e72c1e65cc4686ec082f8cddbe82ed231]