Switcher thread fix

Fixed the mining threads block causing the miner to hang on algo
switcher. Thanks @mrbrdo for the help.
Update configuration.md

Clarification on hamsi-expand-big
some improvements for the zero-hashrate fix, and more debug output
Changed the way hard restart is done for better compatibility with windows pthread.
Update configuration.md

Added extra specifications on the algorithm parameters.
Remove now unused temporary fix for algo switch
nicehash deserve mention for providing bitcoins for stimulation of development. section for future sponsors or special acknowledgments
Updated AUTHORS.md