Log Message:
Changes 4.84:
TL/01 Bugzilla 1506: Re-add a 'return NULL' to silence complaints from static
      checkers that were complaining about end of non-void function with no
      return.

JH/01 Bug 1513: Fix parsing of quoted parameter values in MIME headers.
      This was a regression intruduced in 4.83 by another bugfix.

JH/02 Fix broken compilation when EXPERIMENTAL_DSN is enabled.

TL/02 Bug 1509: Fix exipick for enhanced spoolfile specification used when
      EXPERIMENTAL_DNS is enabled.