[Nano-devel] updates

[David Lawrence Ramsey]

Current changes:

* merged the patch to allow nano to scroll up or down single lines
without scrolling the cursor

* fixed a display problem with Unicode characters that had invalid
widths; giving them a width of zero led to the cursor's being off by one
if the terminal displayed them as Replacement Characters, so they're now
given the width of a Replacement Character

* the code in do_alt_speller() that replaces the text of the current
file with the text of the spell-checked file has been moved into its own
function, replace_buffer(), since it might be useful elsewhere at some
point

* overhauled the statusbar code to remove redundant screen updates, and
to finally handle mouse clicks on the text properly

* fixed the Yes/No/All prompt code to properly handle mouse clicks on
its shortcuts when the MORE_SPACE flag is set

* reorganized the source files: the statusbar code is now in prompt.c,
the help browser code is now in help.c, and the file browser code is now
in browser.c

* added a new -L/--nonewlines command line option, and a new
"nonewlines" rcfile option, to control whether nano adds magiclines to
the ends of files; this required changes to all functions that assumed
that all files ended in newlines; I think I've done this for all the
functions that needed it, but the changes to justify and related code
were extremely tricky, so there might still be a few bugs

* nano now automatically generates an HTML version of the info page,
since (a) it's already used when copying over a new version of nano to
the website, (b) the functionality has been in makeinfo since 4.0, which
came out in 1999, and (c) we already automatically generate HTML
versions of the manual pages anyway

* merged Mike Frysinger's documentation of the additional configure
options into the info page, sorted all the configure options more
consistently, and added --disable-utf8 after --enable-utf8

* the "c-file" regex for characters in nanorc.sample now properly
accepts '\"' and rejects '"' and '''