Bug 12821: Capitalization: about page fixes

Bug 12821: Capitalization: about page fixes

This patch fixes several capitalization issues in the about page.

To test:
- Go to the about page
=> FAIL: you should see
   * Server Information (tab)
   * Koha Team (tab)
   * Koha Timeline (tab)
   * Additional Thanks To... (at the bottom of the Koha Team tab
- Apply the patch and reload
=> SUCCESS: you should see
  * Server information
  * Koha team
  * Timeline
  * Additional thanks to...
- Sign off :-D

Sponsored-by: Universidad Nacional de Cordoba
Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
String changes, no problems found.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>