Nightscape configurable completions

[buster]

unfortunately, the bash completion is still in the wrong order. When completing for "whi", it finds "while" first on my computer, but "which" should be before (c comes before l in the alphabet")...

[nightscape]

Sorting should be fixed now (via compgen -A command {} | sort | uniq in the config.toml).

[nightscape]

I think the configurable completion and runner stuff works quite nicely now (see config.toml), looking forward to additional ideas on what to complete and run :+1:

One thing that's not so nice yet, is that all completers are called when pressing TAB while theoretically only one would currently be needed (I couldn't convince the borrow checker ;). But with the completions I have in my config it's still super-fast, no noticeable lags.

Usually I rebase branches before merging in order to get a cleaner history, but that's a matter of personal preference. Do you prefer to keep the commits in this branch as they are, or shall I clean up before you click the Merge button?

[buster]

Actually, i am noticing some behaviour about the bash compgen stuff i forgot:

Back when i implemented it i had the impression that it looks like some order... But i don't really see a pattern, except that the last command is the most significant..

[buster@Fry➔ ~/projects/rrun] compgen -A command whi
while
which
whiptail
which

[buster@Fry➔ ~/projects/rrun] compgen -A command chr
chrpath
chrt
chromium

[buster@Fry➔ ~/projects/rrun] compgen -A command dir
dirs
directfb-csource
directfb-config
dirsplit
dirmngr
dirmngr-client
dircolors
dirname
dir

[buster@Fry➔ ~/projects/rrun] compgen -A command mc
mc-tool
mc-wait-for-name
mcomp
mcheck
mcopy
mclasserase
mcd
mcat
mc
mcview
mcdiff
mcedit
mcookie

This is particularly baffling. Why is the direct match "mc" not in the last line?! i don't know. But i can't find much documentation of the output format of compgen, so..

I guess just sorting it is the safest bet...

[buster]

Also, i think rebasing might be nice.. :)

[buster]

Also, it doesn't run on my laptop:

[buster@Fry➔ ~/projects/rrun] cargo run 
   Compiling rrun v0.0.6 (file:///home/buster/projects/rrun)
     Running `target/debug/rrun`
thread '<main>' panicked at 'called `Option::unwrap()` on a `None` value', ../src/libcore/option.rs:330
Process didn't exit successfully: `target/debug/rrun` (exit code: 101)

In general, whenever you see an unwrap() call you should really think if this is the way to go. We should try to get rid of all unwrap() calls, to be honest..

[buster]

The error was because i had an old ~/.config/rrun/config.toml file. Working now :)

[buster]

I've made some changed which i think make sense. Specifically, i removed the "echo" completion (what was it used for?), set the browser to "x-www-browser" and changed the helper stuff from ruby to python (ruby is not installed by default on all distributions i know of).

[buster]

I've merged all our changes and released version 0.1.0.

Thanks so much for your changes, Martin! I think this PR has become rather big, so i wanted to get those changes into master...