Use XCAR and XCDR instead of Fcar and Fcdr where possible.

Use XCAR and XCDR instead of Fcar and Fcdr where possible.
* admin/coccinelle/list_loop.cocci: Semantic patch to convert from Fcdr
to XCDR and consistently use CONSP in the list iteration loops.
* admin/coccinelle/vector_contents.cocci: Fix indentation.
* src/callint.c, src/coding.c, src/doc.c, src/editfns.c, src/eval.c,
* src/font.c, src/fontset.c, src/frame.c, src/gnutls.c, src/minibuf.c,
* src/msdos.c, src/textprop.c, src/w32fns.c, src/w32menu.c, src/window.c,
* src/xmenu.c: Changed to use XCAR and XCDR where argument type is known
to be a Lisp_Cons.