Small coding style fixes
Add system information for linux

This adds support for printing system information on linux.
Some minor code refactoring in v4l2 plugin

Small code changes to decrease indentation a little.
Fix a possibly left open file descriptor in v4l2 plugin
Use macro for prefixing log messages in v4l2 plugin
Add more logging to v4l2 plugin.

This adds some mostly user focused logging statements.
Add fallback sizes and framerates to v4l2 plugin.

Until a proper fix is found to support devices that use stepwise
or continuous values for framesize and framerate this adds fixed
values that can be selected.
For devices that support discrete values those are still queried
and used.
Use default color space in v4l2 plugin
Fix update checck bug

Fix bug where updates for windows would check for mac updates and vise
versa.

(I am ashamed)
Fix Jansson dependency importing
Move config include path, so it works for the exported target
Merge pull request #189 from BtbN/cmake_jansson_fix

Fix Jansson dependency importing
Remove Visual Studio projects
Move all data into the subdir it belongs to

Completely removes the build dir in favor of cmake based build layouting
Copy and install PDB files on msvc builds
Add support for build time dependency copying
Update INSTALL instructions for Linux
Remove obsolete FindDirectX.cmake script

There's no need to find DirectX because with VS2013 and mingw it's
already available by default.  Older visual studio versions that didn't
come with DirectX by default are no longer supported anyway.

(Also mingw doesn't currently work at all due to lack of proper headers,
but once they do it'll be available in the same way.  I think.)
Improve additional_install_files for debug/release

This improves dependency copying and adds separated debug/release
install files.
Allow copying of all dependencies (windows only)

If the cmake user variable COPY_DEPENDENCIES is set, this script will
make it so that a windows build will automatically copy all required
dependencies (FFmpeg, x264, and Qt5) to the respective
additional_install_files\exec(32|64) directory.  This makes it much
easier to set up a development environment on windows, and much easier
to make usable test builds.

It will also copy the appropriate Direct3D compiler DLL, along with
dependencies of dependencies (the icu*.dll and EGL/GLES files for Qt)