Update VERSION_STRING in autoconf to 2.3.0-dp2
Update VERSION_STRING in autoconf to 2.3.0-dp2

Change-Id: Iee573bdd88b0aacb24186c141cc7c546dd2082c1
Reviewed-on: http://review.couchbase.org/33999
Reviewed-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>
Tested-by: Mark Nunberg <e7d42768707bf23038325b0b68d4b577e5f6064a@haskalah.org>

mnunberg/libcouchbase,mnunberg/libcouchbase,avsej/libcouchbase,maxim-ky/libcouchbase,maxim-ky/libcouchbase,PureSwift/libcouchbase,mody/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,kojiromike/libcouchbase,senthilkumaranb/libcouchbase,couchbase/libcouchbase,maxim-ky/libcouchbase,avsej/libcouchbase,PureSwift/libcouchbase,maxim-ky/libcouchbase,kojiromike/libcouchbase,signmotion/libcouchbase,couchbase/libcouchbase,mody/libcouchbase,mody/libcouchbase,avsej/libcouchbase,PureSwift/libcouchbase,senthilkumaranb/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,signmotion/libcouchbase,mnunberg/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,mnunberg/libcouchbase,avsej/libcouchbase,mody/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,mnunberg/libcouchbase,PureSwift/libcouchbase,signmotion/libcouchbase,senthilkumaranb/libcouchbase,senthilkumaranb/libcouchbase,signmotion/libcouchbase,kojiromike/libcouchbase