Fix documentation about changing font attributes of existing text

* doc/quickstart.texi (Editing Facilities): Fix documentation: to change
  font attributes of existing text, it has to be marked as an _active_
  region.
Fix typo

* doc/auctex.texi (Selecting a Command): Fix typo.
Update manual

* doc/auctex.texi (Automatic Local): Update description of
`TeX-style-path', `TeX-style-global', `TeX-style-local', and
`TeX-auto-local' variables: there is no need to end directories and
directories lists items with a slash.
Update the FAQ entry about failing `TeX-next-error' behavior

* doc/faq.texi: Update the `Why does 'TeX-next-error' ('C-c `') fail?'
entry, taking into account the `TeX-file-line-error' option.  Update
copyright range.
Add new `ifluatex.el' style
Add new `luatextra.el' style
Add `ifluatex.el' to Makefile.in
Add `luatextra.el' to Makefile.in
Update windows-package Make rule to new Emacs 24.4 package.

* Makefile.in (WEMACSPACKAGE, WEMACSEXTRACTDIR): New variables.
(windows-package): Adapt rule to new Emacs 24.4 package for
Windows.  Use `WEMACSPACKAGE' and `WEMACSEXTRACTDIR'.
Fix structure of the package for Windows.

* Makefile.in (WEMACSDATAROOTDIR, WEMACSSITELISP): New variables.
(WPACKAGEFILES): Update accordingly.
(windows-package): Fix structure of the package for Emacs 24.4.
Reported by Uwe Siart.  Remove the zip package before creating it,
otherwise it would be updated instead of recreated.