Add CCRULE variants for each build type

Add CCRULE variants for each build type

Add explicit LWP, PTH and SHD variants of the CCRULE variable for
LWP, pthreaded and shared-library builds respectively. This allows
Makefiles which support building more than one target type to use
these rules directly, rather than brewing their own.

Modify all of the AFS_CCRULE definitions in the build type specific
Makefiles to reference these rules, so we aren't specifying things
twice.

Change-Id: I79bb394cca8971ce71b10ef55b75d5169bf6b80c
Reviewed-on: http://gerrit.openafs.org/3966
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>