Add Gmail Image Proxy to email apps

[summercms]

I feel kind and thought I'd write this pr for someone else's github issue.

See their github issue here: #127

More info: https://www.scientiamobile.com/what-is-google-image-proxy/

[coveralls]

Coverage increased (+0.02%) to 99.97% when pulling 3232464 on ayumi-cloud:Gmail-Image-Proxy into 880b9fa on WhichBrowser:master.

[NielsLeenheer]

There is something to say for adding Google Image Proxy as an application named "Gmail". But in that case we should not use the application list, but do the detection in PHP, because we do need to reset the operating system.

Even though the user agent string says Windows XP, the actual bot does not run on Windows XP. And neither does the user of Gmail run Windows XP on their own machine.

[summercms]

Therefore Application.php

        /* Gmail Image Proxy */

        if (preg_match('/GoogleImageProxy/u', $ua, $match)) {
            $this->data->browser->reset();
            $this->data->browser->name = 'Gmail Image Proxy';
            $this->data->browser->version = null;
            $this->data->browser->type = Constants\BrowserType::APP_EMAIL;
            $this->data->os->reset();
            $this->data->engine->reset();
            $this->data->device->reset();
        }

Results:

    headers: 'User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko Firefox/11.0 (via ggpht.com GoogleImageProxy)'
    readable: 'Gmail Image Proxy'
    result:  { browser: { name: 'Gmail Image Proxy', type: 'app:email' }, engine: { name: Gecko, version: '11.0' } }

[summercms]

cleaned version: https://github.com/summercms/sc-parser-module/pull/178/files