Memory view in disassembler

Adds a memory view to the disassembler. It can be very useful to have it in the same window when you just want to see what's at a position referenced by a register.
Tab will toggle between the memory viewer and the breakpoint list.
![psp4](https://f.cloud.github.com/assets/4809758/727218/7aabd8de-e17a-11e2-8310-cfc3fe6fdc93.png)