Minor Improvements

Mainly User Interface Tweaks.

1. Version number updated to 2.5.4
2. Zoom Sliders attached to analyser window rather than graph window. See Issue #23
3. Tooltips adjusted for better readability (changed colour and position); Window scrollbars corrected when run as Chrome App #18, #19 and #20.
4. Added Icon and page title for users running in a browser window.
5. Increased the size of the analyser window filter text when shown in fullscreen mode;