Graphical Improvements

[dtcarney741]

1. Highlights should be gradient
2. Scroll bar showing up when it is not needed
3. Grouping/Row Names not resizing and turning into 3 dots, especially in multi-domain matrices. See Being able to resize the DSM graph and the individual columns to allow for wider text to be displayed #57
4. Allow multiple interfaces to be open at the same time on configure visible interfaces screen (also default all interfaces to be checked)
5. View mode option is messed up when switching from interfaces back to names in view menu
6. Add link to user manual in help menu