Editing a CSS file was great, and the revisions integration is brilliant. The only issue I found was it was hard to find my changes way down in a long file, I wish I could toggle the 'same' parts off and just see the changes, ideally with a little surrounding context to understand what/where they are.
when i tried updating the header.php file, I got the following error message:
Notice: Use of undefined constant PHP_BINARY - assumed 'PHP_BINARY' in .../wp-content/plugins/code-revisions/inc/class-code-revisions-editors.php on line 301
Warning: Cannot modify header information - headers already sent by (output started at .../wp-content/plugins/code-revisions/inc/class-code-revisions-editors.php:301) in .../wp-includes/pluggable.php on line 901
Same result on other php pages, even saving with no changes. Going back to the previous page and reloading I find that my change was saved and revisions are displayed.