Fixed performance problem in shader
Fixed bug where av_lockmgr unregistration occurred before avcodec_close at server exit
Fixed bug in channel_producer
#169

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* Created custom decklink allocator for reducing memory footprint.
* Made sure that more threads have the unstructured exception handler installed (avoids crashing the entire process in case of access violations), and thread naming for more threads.
* Ensure that if an exception occurs while rendering the diagnostic window, the window is closed instead of it stopping to respond to window events.
Huge performance impact detected with chroma key support (even though not in use for a layer) in image shader. Straight alpha output support also adds a small overhead (even when not in use), so just like with blend-modes it is now conditionally compiled in the shader, and turned on in the configuration file.

New <mixer /> element added to configuration for turning on mixer features that not everybody would want to pay for (performance-wise). blend-modes also moved into this element:

<mixer>
    <blend-modes>   false [true|false]</blend-modes>
    <straight-alpha>false [true|false]</straight-alpha>
    <chroma-key>    false [true|false]</chroma-key>
</mixer>
CG commands that expects an already running flash template no longer starts a flash player with a template host just to say "no template running on layer". Now only CG ADD and CG INFO creates a flash_producer/flash player if one is not already running on the video layer.
Removed some default values from configuration
Changed order between flash-producer and image-producer so that .ct files gets priority
Flash producer
    - globally serialize initialization and destruction of flash players, to avoid race conditions in flash.
    - changed so that the flash buffer is filled with flash player generated content at initialization instead of empty frames.

OSC
    - merged OSC improvements #152 made by Robert Nagy up until commit https://github.com/ronag/Server/commit/bae86d21f1569b4b7ac1e08c024d62f389efa57e
    - enclosed multiple OSC messages in the same UDP packet inside an OSC bundle to comply with OSC spec
    - ensured that UDP packets are not too big (causing fragmentation, and errors on OSC receiving side)
    - removed use of Microsoft Agents library which seemed to be the cause of running out of memory after a while. Now everything is done synchronously instead (without support for multiple targets, just a single target (parent) for now).
Merge branch 'master' of https://github.com/ronag/Server into ronag-master
Config changes
Fixed bug where optimal code path was never taken when copying frame data in ffmpeg
Fixed serious bug with MIXER LEVELS
Updated documents
Updated version.tmpl
Remove file that should not be checked in, but generated during build process
Updated README
Updated config
Misc. spelling corrections.