Needs gmake to install chem (fixes at least SunOS).
Adding MAKE_JOBS_SAFE=no - parallel building causes the issues reported
by nbjoerg@ and can be reproduced by Joyent bulk builds
fixes missing regeneration of build rule file for subversion-1.8.3.
fixes a patch related to perl binding:
* Update comment, `Second hunk' had been removed.
* fixes patch migration at updated to 1.8.0, original part had been changed,
  but still using old part + additional part.
MAKE_JOBS_SAFE=no, and following failures will be fixed.
* native modules may not be linked against libsvn_swig_perl-1, because module
  Makefile may be created before creating the library, and not found.
* inversely, libsvn_swig_perl-1 of previous version may found, but cannot linked
  because of buildlink sandbox.

Bump PKGREVISION (for safe side with update of patch for Makefile.PL).
Restore support for Clang with libc++11. Bump revision.
Restore Clang support with libc++. Additional changes to deal with the
inability of old GCC versions to cast to int implicitly. Bump revision.
Disable unit tests on SunOS, the build currently fails.