Stabilize @load order in scripts/base/bif/plugins/__load__.bro.

It was ordering differently on various platforms (maybe due to case
insensitive filesystem on Mac).  I couldn't get locale env vars to
stabilize the order of `ls`, so instead piped `find` output through
a case-ignoring `sort`.
Merge remote-tracking branch 'origin/topic/jsiwek/load-order-fix'

* origin/topic/jsiwek/load-order-fix:
  Stabilize @load order in scripts/base/bif/plugins/__load__.bro.