OUSTAT ( selcod, ival, rval, ifail )
====================================

  Output information about the current state of the Kernel

Receives:
  KI_cod_slst              *selcod         --- selection code specifying what
                                           --- information is wanted

Returns:
  int                      *ival           --- returned information (integer)
  double                   *rval           --- returned information (double)
  KI_cod_error             *ifail          --- error code


Description:

  What information is returned depends on the value of 'selcod' :-

  +--------+-------------------+------+----------------------------------------+
  |'selcod'|  interpretation   |return|      interpretation of return value    |
  |  value | of 'selcod' value |      |                                        |
  +--------+-------------------+------+----------------------------------------+
  | SLSTAR | SLST_At_Rollmark  |'ival'| 1 if at a rollmark, else 0.            |
  +--------+-------------------+------+----------------------------------------+
  | SLSTNF | SLST_Num_Forward  |'ival'| number of roll-forward steps available.|
  +--------+-------------------+------+----------------------------------------+
  | SLSTNB | SLST_Num_Back     |'ival'| number of roll-back steps available.   |
  |        |                   |      |   (excluding rollback using ROLBLM).   |
  +--------+-------------------+------+----------------------------------------+
  | SLSTVM | SLST_Virtual_Mem  |'ival'| total bytes of virtual memory currently|
  |        |                   |      |  allocated to the model datastructure  |
  |        |                   |      |  (including free space)                |
  +--------+-------------------+------+----------------------------------------+
  | SLSTFS | SLST_Free_Space   |'ival'| amount of free-space within the        |
  |        |                   |      |   model datastructure in bytes         |
  +--------+-------------------+------+----------------------------------------+
  | SLSTMT | SLST_Maximum_Tag  |'ival'| the highest tag value allocated by     |
  |        |                   |      | Parasolid                              |
  +--------+-------------------+------+----------------------------------------+