Memory viewer redesign

Redesigns the memory viewer to make it easier to use and more useful.

Changes:
-shows bytes instead of words
-selection is one byte instead of one line
-scrolling with page up/down, mouse wheel and arrow keys
-editing hexadecimal and ascii data by typing
-goto address is only executed after hitting enter
-jumping to an entry of the list requires double clicking on it

![memview](https://f.cloud.github.com/assets/4809758/701267/a40dad74-dd6f-11e2-9623-01b3212656c9.png)