Removes temporary stream-based I/O impl
Cleaning
Moves vector size etc to internal signal header
Cleaning
Renames inc_state to inc_state1
Moves scheduling out of inner process loop (RT)
Changes definition of state_t to use vectors for input (only head element used for now)
Renames read_input etc
Generalized read_samp etc in signal to work with arbitrary buffer lengths
Basic vector impl
Fixed AU wrappers to work with vectorized impl

TODO:

	- Remove hardcoding in AU wrapper of step/vector mode
	- Fix support for counter
Tests
Fixes #107
Tests
Cleaning
Collect PortAudio flags
Changes to fa_realloc
Ditto
Adding comments, preparing for refactoring of run_actions

See #110
Changes test_dls to use compound actions (for bettter coverage of scheduling API)