Previously we had two different forgit implementations: one for zsh/bash
and one for fish. In this commit we move the bash implementation of the
forgit functions to the git-forgit script in order to have them in the
form of an executable script. This makes using forgit possible without
any shell plugin at all and furthermore removes the need to maintain a
separate implementation for the fish shell.
The simplest way of using forgit from now on is to put git-forgit
somewhere in your PATH and call it via "git forgit", without the need
for any other files.
We keep the shell plugins, though, and maintain backwards compatibility
by retaining the plugin functions as simple wrappers around the
git-forgit script, making the plugins mainly a collection of aliases
only.
Setting the error option in bash bypasses error handling in the forgit
functions, because the script immediatley exits in case of an error.
Remove the option to make error handling possible.
Bash scripts automatically return the exit code of the last statement,
so standalone forgit will still return useful error codes.
From the standalone forgit command we call the according forgit function
by replacing a '_' with '::'. Since we have more complex function names
like 'forgit::cherry:⛏️:from::branch' we have to replace ALL
instances of '_' instead of just the first one.
Using an underscore instead of a dash simplifies the workflow and
documentation by making the commands and environment variables that
forgit uses the same (i.e. `git forgit checkout_file` is the same
command referred to by `forgit_checkout_file`)
