Make SSL cert verification globally configurable

When debugging using test servers, self signed certificates
are often used for HTTPS. This commit adds a configuration
option that disables SSL certificate verification globally
for all requests made from the mist.io app to the hosted
core service.

The config.SSL_VERIFY option is True by default but can be
overriden in settings.py.
Catch requests.exceptions.SSLError

and raise mist.io.exceptions.SSLError so that it is properly handled
by our exception handler and transformed to an appropriate HTTP
response.

Also deprecate code that authenticates to core service from __init__,
that's handled in check_auth view.
Implement fail counter for backend machines load
Merge pull request #77 from mistio/ssl_verify

Ssl verify
Merge pull request #93 from mistio/backend_enable

Implement fail counter for backend machines load
Automated build of mist.js & mist.css
Disable monitoring when destroying machine or deleting backend

Either directly (when in io/core) context or through API request
in case of standalone io.
Fix weird bug with sudo output redirection in deploy_collectd

In some machines (experienced it in an ec2 AMI vm), doing something
like:
  $sudo echo hello > /tmp/1
will fail with a 'permission denied error', whereas
  $sudo su -c "echo hello > tmp/1"
succeeds. WTF!
Merge pull request #94 from mistio/disable_monitoring_fixes

Disable monitoring fixes