This commit introduces a special case for the restart file writing
code. In particular we no longer write dynamic data vectors (e.g.,
*WEL, *GRP, *CON) to the restart file if we're being asked to output
the initial condition (i.e., report step/sequence number 0).
Add the report step as a new explicit parameter to createInteHEAD()
instead of inferring this value from the "sim_step" and output
dynamic sizes as zero for report_step=0. While here, also correct
an omission from earlier commit 7986e99e. We must ensure that the
maximum number of wells in the field (intehead[163]) is at least as
large as the current number of active wells (intehead[16]).
Update "intehead" test to account for report_step being passed
directly as an argument to InteHEAD::stepParam().