Setting both purge and config_replace to false.

Config settings that have this type of chnage should not be set to true by default. Let
the user decide if they want to be making these changes to their system - I removed my own
sudo access twice before I realized that it was this module doing so (Luckily was on a trash
AWS instance so I didn't mind).
Solution for $sudo::conf not loading in $sudo::params prior to parameters being set.

In the $sudo:: conf definition it was defaulting to a $sudo::params value in one of it's
parameters if they were not set. Unfortunately puppet does not load in including classes (For
example `sudo` was included, which inherits from $sudo::params; however this is not included
until *after* those parameters are set.

The solution inclues still allowing the user to set this parameter, which it defaults to undef. There
is then a conditional that checks if it is undefined, and then sets it to the $sudo::params value - and if
it is defined, it sets it to what was set.
Merge branch 'should_not_replace_current_config_by_default'