ENYO-1420: faster timeout when phonegap is not reachable.

Tested on ChromeCanary/OSX. I do not anticipate any change on other browsers, as it is mainly node.js-side code changes.

The initial issue (Ares server crashing) was fixed by using Node.js domains: https://github.com/enyojs/ares-project/commit/5c7d6d5222181aa68775bc4a81e38e7450f7ec6c

- add configurable timeout when calling build.phonegap.com (default: 7s)
- report actual service error string when checking account

Enyo-DCO-1.1-Signed-off-by: Francois-Xavier KOWALSKI <francois-xavier.kowalski@hp.com>