[V00-22-XX] Misc. bugfixes and updates

**ChangeLog**
- Update _zlib_ to 1.2.8 to match _zlib_ from CMSDIST
- On Darwin use _config.guess_ to get correct machine triplet.
- Enable 64-bit builds for _NSS_ and _NSPR_ on Xeon Phi targets.
- Fix issue where we queue N times `check-<top_level_package>` task, where N is a number of dependencies, i.e., packages we actually need to build. In additional make sure that `serial()` can inform about duplicate tasks, same as `parallel()`.
- Update `isPackageInstalled()` to work with `--no-bootstrap` option, otherwise we add non-existent `install-*` jobs as dependencies and new scheduler goes into a loop.

Tested on SLC6, Darwin, Xeon Phi, ARMv7 (ODROID-U2), and ARMv7 (Dell, Marvell Armada XP Server Board) targets.