ebuilds: correct btsync user setup & correct PID storage location
ebuilds: correct information about user configuration storage location
btsync_setup: correct location for PID storage for system wide systemd service unit
btsync_setup: automatically strip trailing / from HOME env path
update Manifest file
Correct references to openrc & systemd units in restructured /files folder
Add reference to systemd pre-exec setup script (btsync_setup)
Add commented reference to new macro: systemd_newuserunit (currently in Portage Git tree)
Corrected install systemd user unit (using workaround at present)
Updated Manifest file
