Fix export and import bugs

Fix export and import bugs

Our support for exporting and importing config values and expose flags was buggy.  This fixes four discrete but related bugs.

 - Exporting config values would exclude those that had false-y default values.
 - We did not export the expose flag.
 - Importing config values did not work.
 - We called the expose flag "exposed", which is not what the actual delpoyer expects.

To qa, open up the sandbox, deploy apache with "enable_modules" set to something or other, and expose it.  Then export the environment.  When you look at the service in the file, you should see "expose: true" and "enable_modules: mod_proxy" or whatever value you set.  Then reload the GUI and drag the file into the sandbox.  When the service has loaded, you should see that it is exposed, and when you look at the config in the inspector, you should see your value in the "enable_modules" field.

https://code.launchpad.net/~gary/juju-gui/exportBugs/+merge/192286

(do not edit description out of merge proposal)

[gary.poster, 2013-10-23 05:35:07]

Please take a look.

[jeff.pihach, 2013-10-23 16:21:14]

Thanks for this fix! 
LGTM QA OK!

https://codereview.appspot.com/15400052/diff/1/app/models/models.js
File app/models/models.js (right):

https://codereview.appspot.com/15400052/diff/1/app/models/models.js#newcode1193
app/models/models.js:1193: if (service.get('exposed')) {
Maybe we should change what the deployer expects or our service attribute to
match instead of doing this conversion.

https://codereview.appspot.com/15400052/diff/1/test/test_fakebackend.js
File test/test_fakebackend.js (right):

https://codereview.appspot.com/15400052/diff/1/test/test_fakebackend.js#newco...
test/test_fakebackend.js:532: fakebackend = utils.makeFakeBackend();
How did this work before?

[gary.poster, 2013-10-23 16:33:06]

*** Submitted:

Fix export and import bugs

Our support for exporting and importing config values and expose flags was
buggy.  This fixes four discrete but related bugs.

 - Exporting config values would exclude those that had false-y default values.
 - We did not export the expose flag.
 - Importing config values did not work.
 - We called the expose flag "exposed", which is not what the actual delpoyer
expects.

To qa, open up the sandbox, deploy apache with "enable_modules" set to something
or other, and expose it.  Then export the environment.  When you look at the
service in the file, you should see "expose: true" and "enable_modules:
mod_proxy" or whatever value you set.  Then reload the GUI and drag the file
into the sandbox.  When the service has loaded, you should see that it is
exposed, and when you look at the config in the inspector, you should see your
value in the "enable_modules" field.

R=jeff.pihach
CC=
https://codereview.appspot.com/15400052