Changelog updated

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
VERSION updated

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
Compilation fix for MacOSX

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
Fix loading gstreamer plugins on MacOSX

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
Merge pull request #181 from vogel/release-2.1.5

Release 2.1.5