Introduced and implemented OxideSkin which is a skinning interface that
defines the palette that will be used to decorate OxideFrames.

Introduced and implemented OxideDefaultSkin which defines the default
Oxide palette and aesthetic.

OxideFrame, OxideMenuButton: migrated decoration of background colors,
font faces and colors, and control component colors to use the input
OxideSkin instance.
Removed OxidePalette.java whereas it is unnecessary due to the
implementation of skinning.

OxideComponentFactory: the constructor now takes an OxideSkin instance
as input by which the factory member methods will generate UI components
adhering to the aesthetic and palette defined by that OxideSkin.

OxideDefaultSkin, OxideSkin: fixed a member method title typo.

OxideFrame: replaced calls to OxidePalette with calls to the given
OxideSkin.
Merge branch 'introduce_skinning'