get linked [print] selectors working, manual regtest, improved creation errmsg

This adds the feature from #465 (closed).

It also cleans up the creation error-- instead of printing out an oddly formatted binbuf before the creation error (i.e., "... couldn't create"), it puts the binbuf after the error message: e.g., error: couldn't create "foo bar"

This makes things more readable. There are some weird edge cases with escaped semis but it's still preferable to have that content after the error rather than before.

There's also a manual regtest to make sure [print] does all the weird selector handling stuff the same as Pd Vanilla. There may be a discrepancy with "(gpointer)" vs "(pointer)", but I can't imagine anyone depending on that output for anything.