release_notes_3117

Release Notes

TIMESTAMP_LOGS: Fix causing crash in 'clean_pool' and 'balance_pool' with hung builders.
Fix umounting when using MDMFS
Make jail -k try harder to cleanup any messes left behind.
jail -cu: Don't leak host /etc/src-env.conf into jail builds
ZFS Rollback: Fix additional race.
JSON jail: Ignore broken builds rather than corrupting the data
pkg/distclean: Make size calculation account for compressed ZFS datasets.
pkgclean: Clean cache files as well
Don't bother statting or creating pkg cache dirs when deleting them at startup.
poudriere.8: Fix reference to native-xtools and document use of /usr/src
jail -d: Fix not cleaning up jail's temporary mountpoint directory
TIMESTAMP_LOGS: Fix newlines not being handled properly in some cases.