Cleanup UI by disabling useless elements:
- Disable ASCII art commit history graph on the log pages
- Do not show number of affected files per commit on the log pages
- Do not show number of affected lines per commit on the log pages
- Do not show owner for each repository on the index page
- Remove generic description on repository index page
Change-Id: I4df3f24ed9b6b160ecf4aebe8c1fdfb1a339accc