Merge from vendor branch TNF:

Merge from vendor branch TNF:
Import multiskkserv-20100128 as inputmethod/multiskkserv.
Packagesd by Ryo ONODERA in pkgsrc-wip, import requested via PR#43819.

multiskkserv is a skk server which can use multiple dictionaries.
This server uses cdb format as the dictionary format.  cdb is the
efficient and constant (i.e. cannot add, delete, modify) database
format by Dan J. Bernstein, which I think is the appropriate format
for the system-wide constant dictionary storage.