Instead of figuring them out from the string.  This is possible
because those dedicated editing keys cannot be rebound anyway.

This fixes https://savannah.gnu.org/bugs/?49058 reported by Rishabh Dave.

And also case-sensitive searches, backward searches, and searching again.

This fixes https://savannah.gnu.org/bugs/?48987.

This fixes https://savannah.gnu.org/bugs/?48988.

Mentioning "GNU nano" instead of "This program" and referring to the
website instead of to a postal address.

Add the keycodes and routines to allow the user to forego setting the
mark explicitly (with M-A / ^6) and instead quickly select a few words
or lines by holding down Shift together with the movement keys.

(Some combinations with Shift are swallowed by some terminal emulators.
To work around some of those, the combinations Shift+Alt+Left/Right work
as Shift+Home/End and Shift+Alt+Up/Down work as Shift+PageUp/PageDown.)

This avoids showing a ghost item in, for example, the WriteOut menu
when not using --tempfile and the user does not bind 'discardbuffer'.

This fixes https://savannah.gnu.org/bugs/?48751 reported by Andrew Ho.

This also fixes compilation when configured with --enable-tiny.

If this breaks your build, please send report or instructions or patch.

This fixes http://savannah.gnu.org/bugs/?48698

.
Signed-off-by: Rishabh Dave <rishabhddave@gmail.com>

There is no need to specially flag a function key or editing key --
the keycode is indication enough in itself: outside of byte range.

Saving roughly twenty microseconds at startup.

Also, when a key string does not denote a Ctrl nor Meta nor Function key,
there is no point in assigning a keycode, because plain characters cannot
be used as a function shortcut.

The keycode is not a sequence; it is a single integer value.

And instead of using two key types, just use a bool to indicate whether
a keystroke involves Meta.

After initialization, the type of a key is never used nor needed
(other than for meta keys).

And hard-bind the keys Ctrl+Up and Ctrl+Down to these functions.

Unlike the paragraph-jumping code, these new functions disregard
any indentation, treating only blank lines as separators.  They
also do an automatic smart home when that option is set.

This fulfills https://savannah.gnu.org/bugs/?48291.

This allows the user to specify which other characters, besides the
default alphanumeric ones, should be considered as part of a word, so
that word operations like Ctrl+Left and Ctrl+Right will pass them by.

Using this option overrides the option --wordbounds.

This fulfills https://savannah.gnu.org/bugs/?47283.

Don't make it the responsibility of the executed functions to restore
the list of shortcuts of the edit window.  Just detect whether another
menu was displayed, and if so, redisplay the main menu.

This allows for commenting or uncommenting a line or a bunch of lines
with a single keystroke (default binding: M-3).  The characters used
for commenting/uncommenting are specified by the active syntax file.
Reviewed-by: Benno Schulenberg <bensberg@justemail.net>
Signed-off-by: Mike Scalora <mike@scalora.org>

Error messages about lock files should not get overwritten by purely
informational messages, only by alerting ones.

This fixes https://savannah.gnu.org/bugs/?47963.

If during startup there are multiple error messages, currently only the
last one remains and can be read.  To improve on that, introduce a short
pause between error messages -- even if it's not enough to read them all,
at least the user will be aware that there are multiple ones.

This also causes a few error messages to beep that currently don't beep,
such as when a file is unwritable.