Specify how to set a "system property" in the `README.md` file
Update presets to match latest changes in JavaCPP
 * Update presets for FFmpeg where `avcodec` now inherits from `swresample` (issue #13)
 * Skip functions that are not actually implemented in `avdevice`, causing load failures on Android
Update presets to match latest changes in JavaCPP

 * Upgrade presets for videoInput, where the latest code got merged into the master branch
 * Add callbacks for Tesseract according to new functionality in JavaCPP
 * Fix missing dependency of `opencv_contrib` on `opencv_nonfree`