don't trigger default warning handler for inline servers

we already handle server warnings in StashWarnings middleware, so it's not
necessary to do so. without this, under TEST_VERBOSE=1 mode, those warnings
will be bubbled up to Test::NoWarnings handler, which could cause
Test::NoWarnings::had_no_warnings() to fail.
remove diag call in RT::Test::file_content

the main reason to remove it is it causes t/web/cf_access.t to fail no
warnings tests under TEST_VERBOSE=1 mode. the warning is like:

    Name "RT::Test::TODO" used only once: possible typo at .../Test/Builder.pm line 2244

though we can also get around it by increasing $Test::Builder::Level in
RT::Test::file_content or never call file_content in compilation stage(e.g. in
a BEGIN block or "use constant ..."), imo it doesn't worth it.
keep "add principal" input be focused when it's been clicked

when clicking the "add principal" input (e.g. #AddPrincipalForRights-group),
anchor will be synced to #acl-AddPrincipal, but the input focus will be lost
too(at least on firefox).
lock rt-fulltext-indexer so only one instance can be run at the same time

multiple instances eat more cpu and may also break stuff.

see also #17423
avoid adding repeated cf values

now RT::ObjectCustomFieldValues::HasEntry compares LargeContent and also
canonicalizes values before comparision when possible.

see also #4553

btw, there was a bug that if you change a date cf from "2014-05-15" to
"today"(which also means "2014-05-15" at that time), you will get a confusing
message saying "2014-05-15 changed to 2014-05-15". this commit fixes it too.
add --quiet option to make fulltext-indexer more convenient in cron env

so we can exit processes quietly and normally.
tests for repeated values
Minor wordsmithing, and copy the paragraph to Oracle as well
Merge branch '4.0/lock-fulltext-indexer' into 4.0-trunk
Merge branch '4.0/admin-rights-add-principal-input-focus' into 4.0-trunk
Merge branch '4.0/remove-test-file-content-diag' into 4.0-trunk
Bump the Plack::Middleware::Test::StashWarnings dep for "verbose" option

As this is in developer dependencies, there is no harm to doing so in a
stable series.
Merge branch '4.0/stash-warnings-verbose-option' into 4.0-trunk
HasEntry canonicalize values now, so no need to explicitly do that any more
Add initial docs for column maps
Stop mentioning QuickDelete, as it was last useful and working in 3.8
Switch to more canonically useful example plugins
Merge branch '4.0/cf-repeated-values' into 4.0-trunk
Merge branch '4.0/add-columnmap-docs' into 4.0-trunk
CGI.pm will be removed in 5.22; install from CPAN on 5.20 and up

Perl 5.22 will remove CGI.pm from core; using the installed-from-core
version in perl 5.20 produces warnings.  On perl 5.20 and above,
increase the dependency to one that was never provded in core, to force
an install from CPAN.

Fixes I#29053.