Fixed print.css; softer colours; better interval searches

- Fixed print.css, now useful again
- Give priority to day/week/month/year when searching by date intervals, e.g =2d now always means 'in next 2 days' (useful shortcut)
- Softened the colours used for task highlighting, plus a few other styling changes to unify backgrd colours and text colours
- Made keyboard shortcuts more obvious via tooltips
- Allow Esc key from Searchbox to reset it
- Ensure that Searchbox resets properly after a new task is added
- Prevent newlines in Searchbox textarea when entering a search
Fixed print.css; styling changes

- Fixed print.css, now useful again
- Give priority to day/week/month/year when searching by date intervals,
e.g =2d now always means 'in next 2 days' (useful shortcut)
- Softened the colours used for task highlighting, plus a few other
styling changes to unify backgrd colours and text colours
- Made keyboard shortcuts more obvious via tooltips
- Allow Esc key from Searchbox to reset it
- Ensure that Searchbox resets properly after a new task is added
- Prevent newlines in Searchbox textarea when entering a search
line endings changed