* Clarify the license for files we have signoff on
* Update against the currently signed off files
* Remove unused and not clearly licensed headers
* Replace an #endif I accidentally removed while resolving merge conflicts
By testing I found out that, at least on Linux using the Swedish layout,
two macros present on this file were wrong, for the backslash and pipe
keys. Jack helped me find the correct combination for the backslash and
that led me to the right one for pipe.