Nl replaced sync library

Replaced the sync-q library with my own synchronous queue library named - sink_q
Race conditions are fixed so users can call take picture without manually interleaving callbacks

Reviewed By: @johnnyman727
I agree. I was wondering about the SPI bus stuff tho. If there is a shared spi bus then I think that each camera instance should share the same queue otherwise two instances might call take picture at the same time and cause issues. What are your thoughts?