I'm changing the Font class function names:

- SetSize       -> SetFontSize
- GetSize       -> GetFontSize
- SetHeight     -> SetFontHeight
- GetHeight     -> GetFontHeight
- SetWidth      -> SetAverageFontWidth
- GetWidth      -> GetAverageFontWidth

That's because it really makes no sense to say that there is a
single constant font width because obviously proportional fonts
don't have one - the best we can do is an average font width,
which is what folks like Microsoft sort of do already. On a fixed
font, the average is still accurate, for obvious reasons :-)

I'm also not a fan of GetSize/SetSize as I find it a might too
generic.

Change-Id: Ib80a604ba62d6883fd6cbc7994da763976be5c70
Reviewed-on: https://gerrit.libreoffice.org/22069Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Chris Sherlock <chris.sherlock79@gmail.com>