to repeatedly read the conf files. Depending on what is enabled the
files are being read anywhere from 15, 30, or more times currently.
By loading the values in the environment this is reduced to 1, with
perhaps a couple more, again depending on what is enabled.
The speed-up for boot and shutdown is negligible when rc.conf is
on local disk, noticable when accessing files over NFS, and dramatic
when pulling rc.conf values from a database.
This change also includes a minor optimization to the conditional
for $_rc_conf_loaded.
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