Commits work in progress on fixing issues with video capture on Windows.
Commits work in progress on fixing issues with video capture on Windows.
Adds support for immutable and modifiable defaults system properties. (Deployment part pending).
Restores ConfigPropertyVetoException-s

This doesn't change anything semantically since the exceptions could
have already been thrown. They were just removed from the signatures in
an earlier commit and that might have been an omission during
refactoring.
Attempts to fix failures of the Windows Audio Session API (WASAPI) integration which reportedly break the very capture and playback functionality.
Adds support for default configuration properties during name extraction.
Add support for a second defaults file.

The file is named jitsi-default-overrides.properties and it allows a
deployer (system administrator) to keep a separate set of locally
define properties, different from the ones the come with the client.

This commit also allows for zero length override property values.
Makes it possible to override mutability of properties from the overrides file.
Reduces the numbers of times that the camera gets opened and closed on Windows to the minimum, strives to be more thorough about the opening, closing, disposing in an attempt to mitigate issues which could cause the camera to remain open.
Mionr: Use static method throgh class.