generalized readlink location
small documentation fixes
Merge pull request #106 from ahmadia/core_run_job_doc_fixes

small documentation fixes
Merge pull request #107 from ahmadia/fix_build_profile_test_general

generalized readlink location
use absolute paths for temporary directories

This works around an OS X.8 issue where os.path.realpath(d) resolves to
a different dir than d when d = tempfile.mkdtemp()

This PR supersedes #105 and #108
Refactor tests for better portability, other fixes

* added test.utils.which to determine PATH of standard utilities
* added missing "." in test build script
* now using os.path.realpath on run_job tmp directory
lack of /var/lib/dpkg/status == Not a Debian-based system
Fixup for marked_yaml.py move
Merge branch 'master' into spec

Conflicts:
	hashdist/cli/test/test_build_tools.py
	hashdist/core/test/test_build_store.py
Fixup for marked_yaml.py move