Fix generated source packages

There were some issues in what got included when one would do a make
dist. The following files have been added or removed from the output of
make dist:
- Add probes.d file (needed for dtrace probes)
- Remove probes.h file (this must be generated at build time)
- Remove config.h file (overwritten by automake, but will break cmake
  builds from a new source tree)
- remove doc/manout (unused)

Additionally, to help us detect packaging errors, we run the make
distcheck command. The following changes were needed to allow make
distcheck to succeed:
- Add -I$(top_srcdir) - otherwise distcheck (which builds in a
  subdirectory) will fail.

Change-Id: Iae9c51404b3a3771e170e5b4b64205e17854b157
Reviewed-on: http://review.couchbase.org/39317
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Brett Lawson <brett19@gmail.com>