Fix dodgy email-related code
Fix dodgy email-related code

Simplified code to pick contacts and fixed some bugs in SendEmail for Win 8 (not being able to use multiple recipients and not being able to use special characters in the body/subject).

Also removed the callback parameter in SendEmail as it's not very useful and didn't work on WP8.

cedw032/MarkerMetro.Unity.WinIntegration,hungweng/MarkerMetro.Unity.WinIntegration,MarkerMetro/MarkerMetro.Unity.WinIntegration