pkg_install-20091115:
Completely ignore @src in pkg_create. Silently ignore the -L option.
The combination of -I and -p are used by pkgsrc for the same result.

Do not overwrite a string with itself using snprintf. This breaks
setting the pkgdb directory internally on Linux. Explicitly check
if the string is the same and otherwise just use xstrdup.

Add support to query arbitrary variables with pkg_admin config-var.