nnn: Update to 3.1

Package changes:
- Now installs completions for fish, zsh, and bash.
- New option 'mouse' (enabled by default) makes mouse support optional.
- New option 'pcre' (enabled by default) for Perl regular expressions.
- Removed checksum for deleted patch-src_nnn.c in distinfo.

Upstream changes:
- unlimited bookmarks and plugin keys
- status bar text in context color
- support config `NO_COLOR` to disable colors
- config `NNN_OPTS` to specify binary options to `nnn`
- config `NNN_MCLICK` to emulate configurable key
- toggle selection on right click
- ignore hard links when calculating disk usage
- dim (hard/sym) link names (symlink to file has `@`)
- more special keys at empty filter prompt in _type-to-nav_
- key `>` to export file list
- option `-F` to show fortune in help and settings screen
- option `-T` to specify sort order (obsoletes `-v`)
- option to clear sort order
- key `T` to change time type (access/change/mod)
- `.nmv` - internal fully-functional batch renamer plugin
- make var `O_NOBATCH` to disable native batch renamer
- `nuke` & `imgview` - open all images in directory sxiv
- `nuke` - open log files in vi
- plugin `x2sel` - system clipboard to selection copier
- plugin `fzy` - cd using z database
- plugin `fzopen` - support `FZF_DEFAULT_COMMAND`
- create new context on TAB without prompt
- hover and connect by dir name (within config dir)
- move to next entry on current file delete
- on single file copy/move, select the copied/moved file
- option `-f` to to use readline history file (off by default)
- use `s` in status bar to indicate selection in progress
- make var `O_NOMOUSE` to disable mouse support
- do not store `NNN_TRASH` and `-Q` in config/session
- add sample .desktop file for XDG compatible DEs
- rename _nav-as-you-type_ to _type-to-nav_ mode
- fix PCRE case-insensitive regex search
- fix no error msg when filter length limit exceeded
- fix static package generation
- fix broken abort message when started in du-mode
- fix filter lost on context switch in non _type-to-nav_ mode
- fix broken readline prompt
- fix long strings treated as action keys in filter prompt
- fix `NNNLVL` not reset when spawned shell is exited

(sjmulder)