Add CharacterCasing property in MaterialTabSelector and SubtleEmphasis in FontType

[valimaties]

This property will allow users to set CharacterCasing from Text property for each Tab.

Demo:

As long it is my current using branch, I need all properties implemented, so it will include also LeaveOnEntryKey property, which I mention that does not affect current approach for textboxes, as long it is by default False.

Edit: This will add also SubtleEmphasis (MSWord Style) to MaterialSkinManager class. Will allow users to select italic FontType to MaterialLabel

[orapps44]

The code you add in commit 'Restored EnabledChanged event' was removed to fix issue #282, why do you want to add it again ?

[valimaties]

I have conflict in files.. And git shows me that code missing... I though I have to added it.. But, finally, I will remake this branch again, I don't know what is wrong, it shows me wrong code I think!

[valimaties]

I've made all modification to this branch to have no conflicts. Now it is ok.