SMS Module Log - misc UI changes

https://trello.com/c/VrdJJm3T

1 - Rename "SMS Logging" tab to "SMS Log"
2 - Remove line numbers in SMS Log grid
3 - Fix Firefox header column sort icon display bug
4 - Change default SMS Log sort order to reverse chronological order

Change-Id: I59d3d9b373f52e31433c608e868841b22599e0d0