[encoding] bnd files were read with ISO-8859-1 encoding while nowadays most files are encoded with UTF-8. So we now first try to read with UTF-8 and if this fails we fall back to ISO-8859-1. A few places where we were writing it, we also use UTF-8



Signed-off-by: Peter Kriens <peter.kriens@aqute.biz>
[lib] Created a UTF8Properties object that extends Properties but reads properties as UTF8 (with ISO 8859-1 fallback) and always writes them as UTF-8
[launcher] Moved launcher to 1.6 since I needed to write/read UTF-8 props
[utf8properties] Added documentation, improvements and test
Removed the export since it was causing problems if bnd was extended