When Bro was compiled with broker disabled, then some Bro scripts
were referencing functions and types that were not defined. Fixed
by adding @ifdefs to several scripts. Removed one @ifdef because
it was causing several unit tests to fail.
Also fixed the @TEST-REQUIRES check in tests that rely on broker so
that such tests are skipped when broker is disabled.
Simplified some function names, fixed some names of broker script wrappers,
reorder some broker function calls to avoid potential race conditions, and
don't have bro read a trace file when it will not be used.
Also renamed the "print" function to "send_print" and the "event"
function to "send_event" because Bro shows a syntax error when a
Bro script function is named "event" or "print".
