v0.5.0 - First public release

• First public release and version
• dash-fetcher tool to fetch a DASH asset online
• livesim2 server to stream simulated DASH live
• supports SegmentTimeline with $Time$
• supports SegmentTempalte with $Number$
• supports low-latency mode with on-the-fly chunking
• features and URLs listed at livesim2 root page
• configurable generated stpp subtitles with timing info