Move UI to use sizers instead of absolute positioning

[machawk1]

In #302 and 7c9d9a1 we moved to use wxPython "Sizer" layout schemes instead of having to specify the absolute position and size of UI elements, which is inconsistent when the result is compared across platforms.

The other UI tabs/panels should be moved to Sizers as well but are more complicated than the all-button panels of Advanced>Wayback and Advanced>Miscellaneous, which were moved to sizers in the aforementioned ticket.

• Basic - MemGator messages do not appear in Windows UI #290 related, mostly complete in 3e20c9b
• Advanced > Service (Tabular-esque) - State column in missing in Advanced>General on Windows #305, OK and X status overwrite each other in some cases when a service is FIXed/KILLed #226, Consider collapsing the STATUS display and FIX/KILL functionality into one UI element #187 related, mostly complete in
  7f6c4c0 with some alignment issues.
• Advanced > Heritrix (2-column) - In Advanced->Heritrix, display all active Heritrix instances on the system and provide a way to kill 'em #20 related, mostly complete in 109a783

[machawk1]

Services panel mostly converted in 7f6c4c0.

[machawk1]

This is mostly complete and merged into master. However, there is still an alignment issue in the Services tab due to the way sizers are used.

• Fix alignment in Services tab.

EDIT: Fixed in f6c2270