Remove a stray signal handler used for debugging
Send all test servers TERM instead of TERM to apache and INT to plack

Plack handles TERM just fine.  When testing under Oracle, SIGINT is
trapped and ignored by the Oracle client libraries, leading to a
deadlock for any test files which specify actual_server => 1 (or set a
plack web handler explicitly).  SIGTERM is respected, however, and
avoids the deadlock.
Configure an IndexName for Oracle FTS tests

An IndexName became required with 8aad388 despite rt-fulltext-indexer's
fallback of "rt_fts_index", which is the default name created by
rt-setup-fulltext-index.  The test file failed because the indexer
didn't update the index due to FTS being turned off by the config check.
Avoid a warning; FIELD may not be passed to _SQLLimit

This warning crops up when an Oracle FTS query is run.  The _SQLLimit
provides a FUNCTION but no FIELD.
Warnings avoidance on NULL (or blank, for Oracle) description
Show (no value) for an unset new value
Warnings avoidance for empty (meaning NULL, on Oracle) subjects
Warnings avoidance for Oracle

The empty string is the same as NULL in Oracle, leading the Type column
of UserDefined groups to be undef.  Default it to '', which is safe
because no other false value is expected in Type.
We require the user and their schema to exist, for Oracle -- not just the DB
Oracle users cannot have empty passwords -- enforce this

We provide a user password for other databases as well, as it cannot hurt.
Minimal changes to t/api/group.t to not use principals 1, 2, 3

The original implementation of t/api/group.t blindly stuffed principals
1, 2, and 3 into the groups for membership testing.  These are
(respectively) the RT_System user, the RT_System's ACL equiv group, and
the Everyone group.

Clearly, including the "Everyone" group when testing group membership is
a confounding factor.  Create and use three users, instead.  For minimal
changes, these are $users[1] through $users[3], to line up with the
original '1' through '3'.
Merge branch '4.0/oracle-testing' into 4.0-trunk