blocktrans trimmed option removes newlines from contents of blocktrans
and replaces any whitespace at the beginning and end of a line into
a single space. This makes translator life easier.
More detail is described in the bug report.
Closes-Bug: #1583757
Depends-On: I534895be0d5f4bf0429b1511ee5421991386c873
Change-Id: Idb451b7688fd5533a8315399de13bac8b8078a67