Enhancement: allow specification of REPLACEUNCONDITIONAL on PUT

[catherdersoftware]

Currently the Replace option generates a REPLACE keyword. If the data sets are targeted to a specific volume, REPLACE fails; REPLACEUNCONDITIONAL must be used. There is currently no way to trigger this behavior from the FTPBPDSS panel.

Add a Y/N field for REPLACEUNCONDITIONAL, default to N.

[lbdyck]

why not just do the replaceunconditional if replace is specified?

[catherdersoftware]

There are some behavioral differences with the keywords RENAME, RENAMEUNCONDITIONAL, REPLACE, and REPLACEUNCONDITIONAL. You can use REPLACE with SMS and no specific target volume, but you have to use REPLACEUNCONDITIONAL if you do. There are also differences if VSAM or zFS data sets are involved.

Maybe it would be easier to specify the UNCONDITIONAL versions since I believe the intent is to replace the data set no matter what.

[lbdyck]

I'll take a PR if you've time and inclination

[catherdersoftware]

I'll go ahead and do it.