Added Payment API

Jira-issue: WP-651
Added DemoWallet Payment API Implementation

Jira-Issue: WP-651
Fix payment API build errors
Made it more resilient to missing demowallet app.

If the DemoWallet application is missing, it won't crash webinos.
Updated Readme to add special notes for vs 2012

Vs 2012 need extra parameters passed in the npm command.
Merge pull request #43 from gguowei/wp-1121

WP-1121: Automate API dynamic build to defined profile
Merge pull request #42 from andreasbotsikas/WP-651

Added Payment API
Update config_profiles.json with default APIs