Added changelog for version 1.5.2.

Added changelog for version 1.5.1.

Added changelog for version 1.5.0.

Install ffmpeg, ffprobe and rtmpdump tools. JDownloader will use them…

… instead of downloading.

Added changelog for version 1.4.3.

Added changelog for version 1.4.2.

Added changelog for version 1.4.1.

Added changelog for version 1.4.0.

Added changelog for version 1.3.5.

Added changelog for version 1.3.4.