Implement SmartReply/SmartForward for EAS; fixes #2098779

* SmartForward and SmartReply are EAS commands that automatically
  include the original message and, if a forward, all original
  attachments, regardless of whether they've been downloaded to
  the device
* Both commands improve battery life by sending less data; greatly
  so for SmartForward if there are attachments

Change-Id: I12432cd5275a3b54e9a80d5cd59da437c4a086cc
3 files changed