Lots of fixes and changes to the process list. It's shaping up nicely. Still horrible and ugly, but slowly getting a better.

* Fix sorting + filtering.
* Search line works properly and so does user-selection combobox
* Selection and "kill" button works
* Expanding one process expands all its sub children
* Expanding/collapsing the processes will cause the first column to resize.
* Show memory as a nice string (3.4 KB, 12MB, etc)
* Sort memory correctly