update version to 2.4.0.55 for release

add sha3 support, closes gurnec#3

 * also improve file type detection

This is the "Optimized64" implementation from the Keccak Code Package.
The KCP is available from: https://github.com/gvanas/KeccakCodePackage

disable multithreading for very small files

add Catalan language to the installer

associate .asc files with HashCheck

add binary installer