Bug 862311 - [MMS][User Story] Display attachment icon in thread - r=borjasalguero

Additionally, define the thread list item HTML via a template string.

Conflicts:
	apps/sms/index.html

Closes gh-9626
Bug 870124 - [MMS][User Interface] SMS counter display
mock up getSegmentInfoForText
query for the counter only once in thread_ui
text-align: left; for counter in sms