Update mxcfb-kobo.h

Latest version (imx508/ntx, imx507), which, if I understand, covers the
latest Touch, the Glo and the Mini
Update mxcfb-kobo.h

To the latest available version (Kobo Aura).
The AuraHD appears to use the older version.
Minor comsetic tweaks to mxcfb-kindle.h
Tweak the kobo mxcfb cdecl
Update mxcfb ffi stuff
Build CRe w/ kerning support
Tweak CRe's default settings (new installs only).
Merge pull request #199 from NiLuJe/master

Some mxcfb & CRe tweaks