HEAD version now 2.X-devel

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

I now declare HEAD branch "2.X-devel" as it will soon include
work targeted for release post 2.0. 

Those wanting to track 2.0 Releasing Engineering should
check out OPENLDAP_REL_ENG_2 branch.   Developer's should
note that, as in the past, all changes to Release Engineering
branches must first be made to the HEAD branch, tested, and
then back ported as appropriate.  Hence, initial patches
should be against the HEAD branch.

Kurt