Merge pull request #389 from dottedmag/master

Get rid of StartJoin. Great!
Move VHANDLES into EvalContext

This is the tracking of depends_on.
Remove Alphalist

Replace remaining uses with StringSet
Remove unused decl ShowScope
Document what functions in scope.h do
Standardize naming for Scope related functions

But hopefully, Scope will be moved into EvalContext soon, and be
replaced by a proper symbol table.
fix typo for missing -expansion in rhel install instructions
clarify bundlesequence and input mods
Add dmidecode and alphabetize debian paths
Merge pull request #391 from nickanderson/feature/masterfiles/libraries/stdlib/paths/dmidecode

cfengine_stdlib.cf: Add dmidecode and alphabetize debian paths
Add context class for when paths exist
Suppress duplicate selection of value for ping
Per discussion here
https://github.com/cfengine/core/pull/373#issuecomment-13969241
It makes sense for identical os paths to be grouped, but if there is any
difference in a path it should be seperated to avoid context soup. So I
have moved ping into each os context and while doing that alphabatized
the commands.
Merge pull request #394 from nickanderson/feature/masterfiles/libraries/stdlib/paths/suppress_duplicate_ping

cfengine_stdlib.cf: Suppress duplicate selection of value for ping
Merge pull request #393 from nickanderson/feature/masterfiles/libraries/stdlib/paths/exists

cfengine_stdlib.cf: Add context class for when paths exist