gnu: Add Protobuf.

* gnu/packages/protobuf.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.
gnu: Add perl-io-tty.

* gnu/packages/perl.scm (perl-io-tty): New variable.
gnu: Add Mosh.

* gnu/packages/ssh.scm (mosh): New variable.
packages: Correctly handle patching for inputs with no extension.

Reported by Manolis Ragkousis <manolis837@gmail.com>.

* guix/packages.scm (patch-and-repack)[numeric-extension?]: Handle
  FILE-NAME with no extension.
Merge branch 'master' of git://git.savannah.gnu.org/guix into hurd
Final form hurd-minimal package
Patches for hurd source for use in this package