Fix incorrect context bug and move to paths array
The context "all" is not automatically defined like "any", this caused
the automatic contexts for path definition and path existance to never
be defined. Switching to array for path definitions allows the use of
getindices to build the list of all paths automatically instead of
manually. Top level path variable definition for backward compatibility
still exists.
Add and fix redhat and debian paths.
Debian had an incorrect path specified for crontabs.
Added crontab, hostname, and domainname for redhat and debian.
Merge pull request #398 from nickanderson/bugfix/masterfiles/libraries/stdlib/paths

cfengine_stdlib.cf: Fix incorrect context bug and move to paths array, plus crontab fixes.