Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

libedit: Reduce surprising behaviour with filename completion some more:
* Quote '*', '?' and '['. While it may be more useful to expand them to
matching pathnames, this at least matches with the completion we do.
* '@' is a regular character for filenames. Some other shells do
@<hostname> completion but we do not.
* Prefix names starting with '-' and '+' with './' so they are not seen as
options.

libedit: Allow simple quoting in filename completion.

The completer recognizes characters escaped with backslashes as being
literal parts of a word, and adds backslashes to avoid almost all
misinterpretation. In particular, filenames containing spaces can be
completed correctly.

For bug compatibility with the NetBSD version, the improved completion
function has a new name, _el_fn_sh_complete, and _el_fn_complete is
unchanged.

Submitted by: Guy Yur

libedit: Fix a bug that could make completion listings incomplete.

The element matches[0] is the common prefix and is not counted in len, so
subtracting 1 is not needed. A counter for the number of matches per line
was incremented twice.

Submitted by: Guy Yur

libedit: Add basic filename completion code from NetBSD.

This will be used to provide filename completion in sh(1).

Changes from the NetBSD code:
* wide character support disabled, as in the rest of libedit
* config.h and related portability stuff reduced/disabled, as in the rest
of libedit

Submitted by: Guy Yur
Obtained from: NetBSD