and the check wasn't doing the right thing anyway

- rename a bunch of functions
- add/edit debugging messages
- add a safety check to prevent a for() loop from going over bounds

also edit some comments and simplify coincidence test

main data stream

this isn't needed after the autocorrelation chisq element following its
recent updates.

also:

- don't hold the autocorrelation matrix lock when calling gst_pad_alloc_buffer()
- clean up a pair of type casts to avoid accidentally removing a const qualifier
- check for discont flags in addition to time stamp skips when checking for discontinuities

this allows the element to avoid malloc()ing and memset()ing memory when
handling gap buffers when it doesn't need to.  it also prepares the element
for emitting empty gap buffers although that feature isn't implemented yet.

and also edit the debug messages

- rename gst_audioadapter_drain() --> gst_audioadapter_clear()

add an error path to compute_autocorrelation_norm() and check for failure
of this function in the calling code

- avoid making output buffers writable when it can be avoided
- add a throttle to the control queue so that it isn't allowed to grow
  without bound
- fine-grain the locking of the control queue in the sink_chain() function.
  this prevents the code from holding the lock when pushing buffers down
  stream, which might avoid deadlocks if the act of pushing a buffer in any
  way comes back into this element.

This reverts commit 9e5580ed.

added mksyncsink and mkblcbctriggergen also made dt optional for appsync. With dt set to None it just pulls all of the available buffers in order