completion of catch_multiplier

Create a fleet-specific catch multiplier.
So in the catch_Like calculation, expected catch is multiplied by
catch_mult before doing the logL
Also apply the multiplier within Pope's approx and within hybrid so that
adjusted catch is matched to the observed, retained catch
Create these multipliers as additional MGPARM so that they can inherit
time-varying properties
Internally, catch_mult(y,f) is year (not season) and fleet specific
Because it is year-specific in storage (unlike growth which retains
value until changed), a switch within mgparmsetup assures updating for
each year of a block
add FLAG in the data read to indicate which fleets will need a
catch_mult created
Output result in the CATCH section of report.sso