pull changes from master to dev on 2014-06-17

This update brings these approved pulls to the dev branch:
* User-visible:
  * #979: redo of "create game" page to allow limiting by button set, TL status, die skills
  * #967: show option values from previous round during option die setting
  * #973: minor forum look-and-feel fixes
  * #983: add style to in-game skill names so people are more likely to mouse over them
  * #984, #985: make messages friendlier when people access nonexistent or open game pages
  * #986: replace "ButtonMen" with "Button Men" globally
* Ideally not user-visible
  * #950: add game creation time to DB (don't use it for anything yet)
  * #957: add some missing jQuery UI image files to help with the history page
  * #947: refactor of several PHP modules to address code style warnings
  * #972, #982: fix a bug which allowed players to create games between other players
  * #987: move logic for finding button art filenames into the backend

Database updates:
```
00854_game_creation_time_01.sql
00960_unicode.sql.sql
```

(N.B. the `00690_reorder_sets.sql` update was involved in a "change ButtonMen to Button Men find/replace", because i fixed comments in that file.  The update doesn't need to be reapplied.)

Once this pull is merged, i will load the changes on dev.buttonweavers.com as part of #217.