Log Message:
pkgtools/tinderbox-dragonfly: Minor fixes

1) Bulk Build: don't add ports where there's no makefile present (x2)
2) Make hook processing more robust (g option on regex, check for
   non-empty string value)
3) Make enterBuild function work with HOST_WKRDIRS option
4) Handle specific DEPENDS+= case for perl where the addition of the
   dependency port is conditional on the version of perl used.
   This addresses the infinite loop case seen on some perl packages