- Fix build on gcc
Merge pull request #629 from so14k/gcc-build-fix

- Fix build on gcc
Do no try to add empty objects when falling back from yaml
Add 'pkg bootstrap' as it has been added to pkg(7)
Remove deprecated PACAKGESITE from pkg.conf.sample
Import from libucl

Adapt to new API
Remove ustring.h from external
Emit the manifest on the right object
Clarify message about empty catalogs
Free the parser only when needed
Fix json emission
Remove debug
Do no accept unknown user/group in pkg register -i
Simplify parsing with numeric values of for version or name
Add a new pkgdb_close_rw hook
Allow pkg_register_cmd_argv0 to be executed according to argv[0]

Known issues (this only works with 2 arguments and still get the pkg(8)
first arguments)

While here allow pkg_register_cmd to register multiple commands.
Remove debug and properly execute the plugin
pkg_register_cmd_argv0 makes no sense directly creating a binary using libpkg is a better solution
Sync libucl
Print architecture of a package in info output.

Package architecture seems to be an important property for an end user
since there are no other possibilities, such as file naming, to detect
architecture of a package. Therefore, print the architecture in pkg info
output.

Reported by: Eugene Grosbein via irc