Many bug fix

In previous version there were a problem when audio recording was enabled in which after a few seconds of recording Webcamoid freezed, this problem may be solved and audio recording is enabled by default now.

In this version, startup time may be improved after removed unnecessary checks in plugins load. Webcamoid may have a bit slow startup just the first time and load faster in successive runs.

There where many reports of random crashes with almost nothing in common, and I can confirm Webcamoid crashed randomly sometimes, after an exhaustive memory leak scan with Valgrind and Dr. Memory, I found many problems related to how video frames were displayed in the screen, so Webcamoid may be more stable now. Also, enabled linear filtering for frames display.

In Mac, screen capture glitched a lot making impossible to do a smooth screen capture recording, this is because Qt uses Cocoa for screen capture, after adding support for AVFoundation in screen capture, the problem was solved.

Fixed default install paths for Windows installer.

Reduced binary packages size

This time I applied a proper cleaning of debug symbols and unnecessary files, this change is more noticeable for Mac and Windows users. Webcamoid will consume less disc space than before.

Virtual camera for Mac through Syphon

Virtual camera support in Mac is a bit tricky, if you want to share frames with other webcams programs, and do it well, you need to write a kernel extension, and kernel extensions requires signing, and signing requires payment, and at this point is not possible, yet I'm not discarding that option.

So the best solution I've found for now is Syphon for sharing frames with other programs, Syphon is a framework that allow sharing frames as OpenGL textures with other programs also using Syphon. This is More or less a solution for the virtual camera, and I guess most Free Open Source programs will not have problem adding support for Syphon, if they didn't yet, for closed source programs it's a different story.