When searching in system directories for old style dictionaries, also
look in the DICPATH environment variable much like the Hunspell
application does. This gives a lot more flexibility for users and
packagers in finding dictionaries at runtime.

The patch is simple, it just moves a block of code from
GetOldStyleDics that handles searching a directory to a new function,
GetOldStyleDicsInDir. Then if DICPATH is set, its directories are
passed to the new function. Original system directories are also
passed so dictionaries in system-wide directories are found.

Change-Id: I56ac66539495f03f41376b533ca19c6c8d615ec3
Reviewed-on: https://gerrit.libreoffice.org/29543Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: jan iversen <jani@documentfoundation.org>