Fix "Fuel Registration" behavior when there is no Internet connection

[Kate Pimenova]

There is some issues when we try to register new user in case there is no Internet connection.
Steps to reproduce:
Turn off internet connection. Then open welcome page, or Support tab: click to the "Create Account" button, then you'll see the dialog with progress bar.
  Expected behavior: "Create account" button should be disabled during request process. And it should be disabled in case of "Internet Connection error"
  Observed behavior: Button enabled

The same behavior for "retrieve password" button.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/174436

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/174436
Committed: https://git.openstack.org/cgit/stackforge/fuel-web/commit/?id=ca588b0e0a1d7b7c38bc7d9bf735a26deadd6648
Submitter: Jenkins
Branch: master

commit ca588b0e0a1d7b7c38bc7d9bf735a26deadd6648
Author: Kate Pimenova <email address hidden>
Date: Thu Apr 16 18:09:28 2015 +0300

    "Fuel Registration" behavior is fixed when there is no Internet connection

    Closes-Bug:#1443392

    Change-Id: Idc2941ebb646e02cd73c63e51683410599f40cfb

[Anastasia Palkina (apalkina)]

Verified on ISO #360

"build_id": "2015-04-28_22-54-38", "build_number": "360", "release_versions": {"2014.2.2-6.1": {"VERSION": {"build_id": "2015-04-28_22-54-38", "build_number": "360", "api": "1.0", "fuel-library_sha": "0e5b82d24853304befb22145ac4aaf3545d295e1", "nailgun_sha": "5753e0ce613473381a63c63d4309777fce4bea70", "feature_groups": ["mirantis"], "openstack_version": "2014.2.2-6.1", "production": "docker", "python-fuelclient_sha": "8cd6cf575d3c101dee1032abb6877dfa8487e077", "astute_sha": "04ebab96d57b0e8acbf2d7f3ba05e4fbf31b741e", "fuel-ostf_sha": "b38602c841deaa03ddffc95c02f319360462cbe3", "release": "6.1", "fuelmain_sha": "ee112acfdd0f9017ef40be53e8e51bb5c429e97c"}}}, "auth_required": true, "api": "1.0", "fuel-library_sha": "0e5b82d24853304befb22145ac4aaf3545d295e1", "nailgun_sha": "5753e0ce613473381a63c63d4309777fce4bea70", "feature_groups": ["mirantis"], "openstack_version": "2014.2.2-6.1", "production": "docker", "python-fuelclient_sha": "8cd6cf575d3c101dee1032abb6877dfa8487e077", "astute_sha": "04ebab96d57b0e8acbf2d7f3ba05e4fbf31b741e", "fuel-ostf_sha": "b38602c841deaa03ddffc95c02f319360462cbe3", "release": "6.1", "fuelmain_sha": "ee112acfdd0f9017ef40be53e8e51bb5c429e97c"