Added support for proxy authentication params

* Added proxy_{user,pass} to init manifest.
* Updated params.pp to accept proxy_{user,pass}.
* Updated config_teagent.sh.erb template to accept proxy auth
parameters.

Signed-off-by: Shashank Sahni <shredder12@gmail.com>
Updated commands to use full path names

* Updated teagent::repository manifest. Using full path for 'apt-key'
and 'rpm'.
Merge pull request #1 from shredder12/master

Added proxy auth support