Modern libraries do not handhold the user into just calling the header,
instead they namespace it, e.g. libevdev/libevdev.h. Because we already
install our headers under the libx52/ directory, having the pkg-config
files specify `-Ilibx52/` is a legacy from the old days, and should no
longer be used.
This commit also adds pkg-config files for x52dcomm and vkm, installing
them in their proper locations.
Previously, x52d had conditional compilation flags linking to libevdev
on Linux. However, I wanted to change this so that we use an abstraction
layer that will link to the appropriate backend (evdev on Linux only for
now). The idea is that we get rid of all conditional compilation blocks
and deal with the backend through the vkm library.
This new library handles the mouse scrolling, clicking, as well as
adding the ability to include keyboard events so that we can support the
profiles feature in a future commit.
nirenjan