Adapt P4Ruby for 2005.2 API changes.
The 2005.2 API supplies forms
ready-parsed in tagged mode and in general P4Ruby worked with it. The
only issue was that P4Ruby wasn't caching the specdefs properly so
conversions in the reverse direction were broken. This change ensures
that we cache the specdef if we have it regardless of the API level.
Squelched on a compiler warning too while I was there.