Add "emergency word-wrap" to strings in proofread mode

When very long words appear in the source or the translation,
they overflow in an ugly way. This commit adds word-wrap that makes
sure that they will break more gracefully.

Change-Id: Ibbaf68dba3cea1a05150855a1ba48c1dd41a2c8b
Merge "Add "emergency word-wrap" to strings in proofread mode"