Warn users against editing compiled stylesheets

New contributors occasionally edit the compiled stylesheets in
media/redesign/css. When they run `compile-stylesheets`, their work is
overwritten.
Merge pull request #2446 from openjck/compiled-stylesheets-warning

Warn users against editing compiled stylesheets
Use hardcoded logger name for now.
Increase amount of memory assigned to VM to 1GB.