Be more verbose when parsing repositories configuration files

Do not fallback anymore on yaml for repository configuration files, it
should just be "normal" ucl given it is a new configuration file.

While here add some debug information when parsing a repository
Do no silently ignore unknown configuration entries.

Fix a double '/' in repository file path
Sync from libucl
Let archive_read_open_filename handling reading from stdin

Previous code was leaking file descriptors unclosed leading to pkg repo
being able fail because of "too many open files"

While here properly close archives after reading

Reported by:	Kris Moore
Properly close the archives before freeing them
Drop support for libarchive older than 2.8.4
Remove unused PKG_STREAM type
spelling: grap -> grab 

just one char! :)
Merge pull request #679 from seanchannel/patch-1

spelling: grap -> grab
pkg.8: Fix my personal email
Fix segfault in pkg audit -F

Submitted by:	many
Fix segfault in event pipe

Reported by:	kmoore
Merge branch 'master' into docco