Fix trying to delete dirs, during force reinstall, that should be kept.

Related to bda157aa3 b4dd0da6 65acd4e57
Fix `pkg check -d` and `pkg query %d` not returning missing deps

This needs to be a LEFT JOIN instead of INNER JOIN since the
package entry may be missing. It's still a valid dependency
though and should show up under PKG_LOAD_DEPS

Broken by 7021b09df
Fix some indentation
pkg repo -F create the file database along with the regular package repository.
Spelling

Reported by:	matthew@
Wording

Reported by:	matthew@
Fix `pkg install -R` not installing missing dependencies

This is fixed by including missing dependencies into the jobs
after including the upwards dependencies into the list.

Fixes #430
Fix grammar of usage
Use consistent 'usage:' syntax
pkg-convert.8: Add missing pkg-shell(8) reference
Add missing pkg-convert(8) references
Update document dates
pkg.8: Document 'convert' subcommand
Add missing pkg-convert(8) reference
Update document date
Do not install libelf headers
Fix build with gcc 4.7 by removing a useless assert
Fix build with gcc 4.7
Merge remote-tracking branch 'upstream/master'