Update presets to match latest changes in JavaCPP

* Upgrade presets for FFmpeg 2.4.2, LLVM 3.5.0
 * Include new `createIndexer()` method in `CvMat`, `IplImage`, `Mat`, etc. for easy and efficient multidimensional access of data ([issue #317](http://code.google.com/p/javacv/issues/detail?id=317))
 * Deprecate `get*Buffer()` methods in favor of a better named and generic `createBuffer()` method