Defined minimum window size.
Fixed sizing of superview.

Bottom edge extended beyond the edge of the window, making resizing
difficult.
Allowed resizing of NSTabView and parents.
Defined sizing of Tools tab contents.
Defined sizing of Schedule tab contents.
Defined sizing of Repos/Recipes tab contents.
Defined sizing of Install tab contents, tweaked Tools tab.

Also changed wording of Xcode CLI info text.
Fixed logo display bug on Install pane.
Merge pull request #69 from lindegroup/resizing-behavior

Defined window resize behavior on all tabs.