get_data_dir(): Handle manually created poudriere/data datasets properly
status: Fix -H output
jail -i: Use 'method' instead of 'acquired' which matches other documentation better
detect whether portsnap supports interactive-flag

Submitted by:	Reinier Schoof <reinier@skoef.nl>
jail: Stop showing arch/mnt warnings for non-existent jails
Replace all MASTERMNT= with _mastermnt() call
Return proper dir from get_data_dir()
Use shorter mount path (based on SHA256 of MASTERNAME) to work around short mount path restriction of MNAMELEN(88)

Ticket:	[165b132e6d]
new_packages -> npkg to work around low MNAMELEN

Ticket:	[165b132e6d]
Shorten injail mount of /poudriere to /.p to work around low MNAMELEN

Ticket:	[165b132e6d]
Only use hashed version if MASTERNAME exceeds MNAMELEN and also check if it is still too long and show reason.

Ticket:	[165b132e6d]
Support including [jail-][ptname-][setname-]poudriere.conf in poudriere.d

Ticket:	[dc8cbd6acb]