Cleaning up warnings view

[vlidholt]

Never happened for the 1.0 release, but should be fixed. The warnings view doesn't look too great. Fixes that should be done:

• There should be no focus ring when the table view is selected (use the CCBTableView in Interface Builder).
• The font should be smaller. Use same font as in the timeline.
• Selecting items should not use standard blue color, but use same selections visuals as in the file list.
• Would be nice to use the yellow warnings triangle in front of each error message.

[NickyWeber]

An addition: What about going XCode and this status to the middle of the tool bar, which is quite empty:

In case of warnings this would show up prominently at the top. A click would open the warnings pane.

[NickyWeber]

Added changes in "Feature/#318 cleaning warnings" #337

[vlidholt]

Can still use some tweaks (warning icons), but good enough for now. Moving it up a milestone.