[OFFAPPS-210] Truncate table headers

:art:

Truncate table headers.

![](http://f.cl.ly/items/2r13012P0x2a091v2Q2G/Screen%20Shot%202013-12-12%20at%2011.46.52.png)

JIRA: https://zendesk.atlassian.net/browse/OFFAPPS-210

/cc @maximeprades