Allow specifying vertical alignment of text in label widgets

[squiddy]

Current behaviour

As you can see, currently text is always vertically centered. This is hardcoded here: https://github.com/fifengine/fifechan/blob/master/src/widgets/label.cpp#L134

What I want

Be able to specify the vertical alignment, similar to what is possible with horizontal alignment right now.

setAlignment(top);
setAlignment(center);
setAlignment(bottom);

[helios2000]

Ok, but then we need 9 instead of 3 alignments.
Left, Center, Right and the new ones Top, Bottom, TopLeft, TopRight, BottomLeft, BottomRight.
Or what do you have in mind?

[jakoch]

Notes

• Graphics already has an Alignment enum, which could be extended, like helios suggested.
• We could also keep Alignment (as this is a horizontal alignment) as it is: Left, Center, Right
  and add an additional VerticalAlignment with Top, Center, Bottom.
  This enables the user, e.g. to use Alignment: Right + VerticalAlignment: Top to position a label TopRight.

Todo

• setVerticalAligment, getVerticalAlignment
• mVerticalAlignment, enum
• update Label draw method