merge sent-feedback-1244.  provides: positive feedback when sending a message.  also stops draft-saving loop from continuing after compose is dismissed.  author: moe, reviewer: glyph.  closes #1244, #1293
merge sent-feedback-1244.  provides: positive feedback when sending a message.  also stops draft-saving loop from continuing after compose is dismissed.  author: moe, reviewer: glyph.  closes #1244, #1293

twisted/mantissa,twisted/mantissa,twisted/mantissa