Log Message:
Update to 1.0.3

Changelog:
- 7/4/2019: version 1.0.3
  This is a binary compatible release.
  * resize fixes for Nx1 sizes and the addition of non-opaque alpha values for
    odd sizes (issues #418, #434)
  * lossless encode/decode performance improvements
  * lossy compression performance improvement at low quality levels with flat
    content (issue #432)
  * python swig files updated to support python 3
  Tool updates:
    vwebp will now preserve the aspect ratio of images that exceed monitor
    resolution by scaling the image to fit (issue #433)