Merge pull request #30 from biometrics/stream_processing

some updates to buffer management
maintainance
fixed edge case
hid QCoreApplication from API
bug fix introduced by previous commit
the worst bug in the world
doc tweaks
refactored future waiting
more future refactoring
bug fix
more plugin development
Add support for multi-threaded execution of time invariant stages of a stream
Fix a crash in Show2 transform

Send a deep copy of the current image to the GUI thread, copy must be called
explicitly or a shallow copy will be done, and subsequent modifications to the
buffer will cause crashes when the GUI thread tries to draw it.