Fix for task 1991.

We were using a hard coded path for the failsafe policy, this change
makes sure we honor the compile time path given by the user.
Factor out verify_outputs.h
Factor out processes_select.h
Factor out files_copy.h
Add cf-key into tests' workdir
Remove redundant stub
Remove useless yyerror call in SetAuditVersion
Move proc_keyvalue to libutils
Generic LinkedList implementation.

Data agnostic linked list using reference counting to provide both
implicit sharing and copy on write.
Merge pull request #289 from cduclos/master

Generic linked list implementation
Style corrections for new list, refcount
Move statistics to libutils
Take out some more misplaced FatalErrors, reduce reliable on eval state
Unexport CopyFileSources
Unexport FSWrite
Unexport DeleteHash
Unexport NewHashValue
Unexport SourceSearchAndCopy
Unexport VerifyCopy
Unexport CopyRegularFile