* plugins/base: code style improvements
Quote variables, use $@ and $array[@] instead of $*, typeset some integers, remove unneccesasary binary invocation, use shell features when possible, remove `eval`, &c.
* plugins/base: conditional function definitions
Instead of functions failing when required tools aren't installed, just don't define the function.
Alsö, don't redefine del() if it already exists.
* plugins/base: rewrite `usage()`
Reimplement disk usage function using Bash syntax and simpler layout, without having to invoke an external binary.
* plugins/base: revamp `quiet()`
New implementation that is even quieter.
* plugins/base: `myip()`
* plugins/base: `pickfrom()`
* plugins/base: `passgen()`
Fix `passgen()` to not need `tr`, remove one subshell, and eliminate a useless `echo`.
* plugins/base: `mkcd()`
* plugins/base: `mkiso()`
* plugins/base: remove `banish-cookies()`
Adobe Flash is gone with the wind. Alsö, this would be something someone would do *once* and shouldn't be a function...
* plugins/base: `lsgrep` is SC2010
The `lsgrep()` function is *itself* explicitly forbidden by `shellcheck` rule SC2010.
Alsö, s/`$*`/`$@`
* plugins/base: `mkiso()`
Expressly handle unbound parameters.
* plugins/base: remove `command_exists`
* plugin/base: lint SC2154 && SC2144
Newly undisabled `shellcheck` rules
* plugin/base: import libs for tests
* plugin/base: `shfmt`
Apply `shfmt` using current project settings. My apologies to future `git blame` hunters. ♥
c2c76a380a