[WIP] Diamond search for quarter resolution motion estimation
Created by: magwyz
This branch adds diamond search for quarter resolution motion estimation on top on the diamond search for half resolution. Compared to master, the total speed-up on objective-1-fast is approximately 10 %. In the current state, most of the samples have their rate distortion curves not modified, others have a limited regression and the Wikipedia sample is really badly encoded.
Here are the AWCY runs: https://beta.arewecompressedyet.com/?job=diamond_me_hres_test%402019-03-15T17%3A06%3A10.611Z&job=master%402019-03-18T14%3A11%3A44.194Z&job=diamond_me_qres_test%402019-03-18T14%3A10%3A31.111Z