[compdat] Add support for opening/closing connections with WCONPROD/WCONINJE

[lindjoha]

Add support for closing and opening connections with WCONPROD/WCONINJE. Example:

COMPDAT
  'OP1' 1 1 1 1 'OPEN' /
/
WCONPROD
  'OP1'  'SHUT'  'ORAT' 1000 /
/

This should SHUT the connection at that date.