Add custom stylesheet for documentation generated by doxygen.
Add obs logo to be used with doxygen.
Add custom header for doxygen.

We use a custom header to add source sans pro.
Add doxygen configuration file for obs.

This will currently only generate documentation for libobs.
Some documentation improvements in obs.h

A stub for the main documentation page was created.
Some documentation improvements in obs-properties.h

Create a stub for the documentation page.
Some documentation improvements in obs-module.h
Some documentation improvements in obs-source.h
Some documentation improvements to obs-service.h
Some documentation improvements to obs-encoder.h
linux-v4l2: Fix select in capture thread.

This moves the enabling/resetting of the file descriptors inside the
capture loop so it is done before each select call. Why this even worked
before is unclear, but doing it the *right* way seems to reduce latency.
linux-v4l2: Make timestamp offset local.

This replaces the var in the source struct that are handling the
timestamp offset with a local one in the capture thread.
This change is mostly to make the code more readable.
linux-v4l2: Make frame counter local.

This replaces the var in the source struct that was used to print out
the number of captured frames with a local one.
linux-v4l2: Avoid nested device open/close.

This moves the calls to the property modified functions so the old
handler can close the device. Otherwise this would cause the device
to be opened multiple times.
linux-v4l2: Always display currently selected device.

This adds some code to the device enumeration that checks if the
currently selected device is present. In case it is not it will
add the device but disable it.
linux-v4l2: Disable properties when device is not there.

This adds helper function to disable/enable all properties which is
used in the device selected callback to enable/disable the properties
when the selected device is available/unavailable.
linux-v4l2: Update properties when devices change.

This causes the properties for v4l2 sources to be refreshed when a
device is disconnected/connected.
Merge pull request #290 from jp9000/v4l2-improvements

linux-v4l2: Handle reconnection in properties
Merge pull request #287 from fryshorts/doxygen

Add Doxygen configuration for creating api documentation
mac-syphon: Move release calls to helper function