Terminus site backup get --element=db #215 - #217

@jcandan quick question, why not just normalize the value at the site() function of php/commands/site.php. Just curious. This looks good to me.

not sure what you mean by "normalize the value at the site() function of php/commands/site.php". could you elaborate?

@mikevanwinkle made suggested improvement. let me know your thots. thx!

This also addresses #216.

@jcandan I just meant that if you modify site.php to transform "database" into "db" then all the changes to the Environment file seem to be unnecessary. I feel like one place of the other should be responsible for the transformation and not both and I was just curious why you picked Environment.php instead of site.php.

@mikevanwinkle I guess I was thinking it'd be best to correct the bug, since db is what the help documentation shows, and is used correctly in other places. I only added the transform for backwards compatibility (good idea btw). however, one plus with this setup is that at some point in the future you can deprecate and remove database as a valid option.

@mikevanwinkle, so, what do you think?
A) should i remove the work done in Environment, and we just go with a handshake in site.php to translate db to database? or
B) do you like the idea of Environment correctly taking db as per documentation, and site.php translates database to db for backward compatibility (as is currently done in my patch)?

@mikevanwinkle so, no go, eh?

This looks good,, @jcandan. Thanks! I'll merge it into master.