HiDPI theme

[Lukas F. Hartmann]

Dear XFCE4 devs,

I chose XFCE4 as my primary desktop environment on Debian Testing when I
installed it on an Apple rMBP about 4 weeks ago. I'm very happy with the
speed and usability, but I had to make a custom high-resolution WM theme
for it to be really enjoyable on a 140 DPI setting. The 13" monitor has
a resolution of 2560x1600. The WM theme has extra large titlebar buttons
and thicker borders to make resizing more comfortable (it's really hard
to aim at a 1px border at this resolution).

Because there is no HiDPI theme in the XFCE default theme choices, a
friend suggested that I inform you of my theme's existence. In case this
is interesting for you, I would draw the remaining titlebar buttons (I
currently only use C, H, M) and do any suggested cleanups that are
required for inclusion in XFCE.

Here is the theme including a screenshot:
https://github.com/mntmn/xfce4-hidpi-theme

Cheers,
Lukas (mntmn)