Add debug output to readerd

Trap invalid messages resulting in:

readerd-1a7ba35: user error (Pattern match failure in do expression at
src/ReaderDaemon.hs:108:13-51)
Use strict foldl'
Correct code automatically setting capabilities

Set number of capabilities to either the value set on the command line
or to the total number of processors on the system if unspecified.
Merge branch 'master' of github.com:anchor/vaultaire
Correct missing imports