Codesign: Allo non-zero exit code for signtool on Windows

Tracking: Refactor autotrack tracking implementation

The idea is to avoid any synchronization needed in the worker threads
and make them to operate on a local data. From implementation detail
this is achieved by keeping track of "wavefront" of markers which are
to be tracked and the tracking result. Insertion of results to the
AutoTrack context happens from main thread, which avoids need in the
lock when accessing AutoTrack.

This change makes tracking of many (300+) about 10% faster on the
Xeon) CPU E5-2699 v4. More speedup will be gained by minimizing
threading overhead in the frame cache.

Another important aspect of this change is that it fixes non-thread
safe access which was often causing crashes. Quite surprising the
crash was never reported.

Libmv: Tweak default logging verbosity level

Log to verbosity level 1 rather than INFO severity.

Avoids a lot of overhead coming from construction of the INFO stream
and improves performance and threadability of code which uses logging.

This makes tracking of 250 frames of a track of default settings to
drop down from 0.6sec to 0.4sec.

Libmv: Cleanup, remove unused logging macros

Unused and was not entirely happy with such short abbreviations.

Cleanup: De-duplicate object mullptr checks

Makes it more clear whether object is allowed or not allowed to be NULL.
Also, avoids possible access to the different object mode enumerator.

Should be no functional changes.

Tracking: Clarify tracks and options storage once again

This is something not-so-trivial to see from just reading code, which
shown an important of proper comments and clear naming.

Main source of confusion was that it is not immediately clear that
AutoTrack context is to see all tracks, but tracking to only operate on
selected ones.

Tracking: Make image accessor own what it needs

Previously image accessor was sharing array pointer for tracks access.
Now it is possible to pass a temporary array valid only during the
initialization process.

Should be no functional changes.

Tracking: Cleanup, remove unused argument from image accessor

Tracking: Cleanup, remove unused field

Was re-introduced after previous round of cleanups when was merging
refactor and master branches.

Tracking: Cleanup, use explicit frame match option

No functional changes, just allows to potentially extend the options
in the future, and also makes code more explicit.