Merge pull request #76 from ruvolof/master

Fixed multi-shell handling.

Last merge was about shell connecting to more daemon simultaneously, while this merge is about daemon correctly handling different shells. And tests output works too (almost, check email for details).
erased Proc::Spawn from shell include files
fixed: Uknown options shell-path for services
added command history to the shell. Up Arrow works
Install.pl: added Term::ReadLine::Gnu for command history
fixed do_all socket identity
fixed full_cache shell-path getopt
Merge branch 'master' of git://github.com/cvmfs/cvmfs
fixed typo
changed identity separator. Fixed compiling zpipe
fixed ipv6 address in ipv6_fallback test