They have been flawed ever since nxagent came up, as they were Xfree
 (non-capital f) always, but should have been XFree (capital F, defined
 in Xlibint.h and part of libNX_X11).
 .
 Probably this all should be free() all over the code (bearing in mind,
 that XFree() returns int, not void. But still...

 Fixes ArcticaProject/nx-libs#553.