add icon to history button
Add diff
Improve diff
remove br
replace tabs
escape html
Add diff views
remove line
Merge branch 'diff' of robinson.informatik.uni-bremen.de:awe11 into diff
fix diff
remove cancan from gems
Merge commit 'c6c501fcd4b50e45a7e8af4bb86f5084b441c6be' into diff
replace differ by diffy
include plus/minus
add surrounding lines
Add cool diff highlighting
add diff info
Improve highlighting