Restore recursive tap search

Fixes #28234.
GithubGistFormula doesn't need to know the exact signature of initialize
opencbm 0.4.99.97: open Commodore device access

Provides disk and other device manipulation programs for Commodore
Business Machine peripherals such as the 1541/1571 disk drives (often
used with the Commodore 64/128) and printers.

Added initial revision of opencbm tools for accessing Commodore disks,
printers, etc.

Tested to work under OS X 10.9/x86-64 and 10.4/ppc using tigerbrew.
opencbm: add 0.4.99.97 bottle.