Manual provider fails when trying to bootstrap a Saucy machine

[Chris Glass]

When trying to use the manual provider to bootstrap a new environment on Saucy, the bootstrap command fails with the following:
https://pastebin.canonical.com/99579/

Machines involved:
- "localhost" : Saucy desktop install, up to date, juju version: 1.16.0-saucy-amd64
- "bootstrap node" (in the traceback that is 192.168.122.254): KVM instance, fresh saucy server install.

Steps to reproduce:

1. Install a fresh saucy server install in a KVM
2. On a desktop Saucy machine install juju: sudo apt-get install juju-core
3. run "juju init; juju switch null"
4. edit ~/.juju/environments.yaml, add the KVM IP address as "bootstrap-node" in the "null" provider.
5. (optional) run "ssh-copy-id $KVM_IP"
6. run juju bootstrap --show-log --debug -v

Result:
The bootstrap fails because while the saucy tools are apparently downloaded, they are not part of the list juju considers: the log shows "Filtering possible tools: 1.16.0-precise-amd64;1.16.0-precise-i386"

Expected result:
The downloaded tools are available to juju when filtering possible tools, and the installation continues.