* Switch order of "apt" and "aptitude" for detection
"apt" is installed by default at Debian (maybe Ubuntu too), while "aptitude" does not seem to be installed by default.
For that, it may be better for most of the users to prefer "aptitude" if installed.
* plugins/debian/README: Change of order mirroded into documentation
There appears to be a definition issue for some functions/aliases which
result in the following errors when sourcing .zshrc:
```
/home/username/.oh-my-zsh/plugins/debian/debian.plugin.zsh:75: defining function based on alias `abd'
/home/username/.oh-my-zsh/plugins/debian/debian.plugin.zsh:75: parse error near `()'
```
Fixes#7986
* Use double quotes to cache value of $apt_pref and $apt_upgr
* Clean up and fix syntax of command checks
* Clean up README and document $apt_pref/$apt_upgr overriding mechanism
* Rename `ag` alias (apt upgrade) to `au`
* Clean up README and fix syntax
Fixes#3686Fixes#4660Closes#5906
Co-authored-by: Noah Vesely <fowlslegs@riseup.net>
The debian plugin calls which to determine whether aptitude & sudo are
installed. However, if these are not installed then the error output
from which will be output. Since this isn't really an error condition,
this commit updates the which calls to pipe stderr to stdout, thus
hiding the error messages.
