Lire: CEDD linear search now 10% faster

Due to comments from a friend I re-investigated the Tanimoto coefficient implementation of the CEDD class and could just delete an unnecessary “if” statement. This results in a 10% speedup in tests of linear search with 150k images. With the new implementation search takes ~460 ms (averaged over 10 runs) on a 64-bit VM, quad-core, 8GB RAM with the index being on a SSD. Find the new version in the SVN.