This will put whatever git's default merge variant is as the first menu item,
and add a second item which is the opposite (no-ff if the default is ff, and
vice versa).
If users prefer to always have the same option first no matter whether it's
applicable, they can make ff always appear first by setting git's "merge.ff"
config to "true" or "only", or by setting lazygit's "git.merging.args" config to
"--ff" or "--ff-only"; if they want no-ff to appear first, they can do that by
setting git's "merge.ff" config to "false", or by setting lazygit's
"git.merging.args" config to "--no-ff". Which of these they choose depends on
whether they want the config to also apply to other git clients including the
cli, or only to lazygit.
This is an object that is owned by Gui, is accessible through GuiCommon.State(),
and also passed down to GitCommand, where it is mostly needed. Right now it
simply wraps access to the Git.Paging config, which isn't very exciting, but
we'll extend it in the next commit to handle a slice of pagers (and maintain the
currently selected pager index), and doing this refactoring up front allows us
to make that change without having to touch clients.
Many people don't understand what this means, which is apparent from the amount
of issues that got filed because of this. Let's get rid of it to avoid this
confusion. People will have to configure their pager twice if they want to use
it both on the command line and in lazygit, which I think is not a big deal.
The actual usage is case insensitive, so this doesn't actually matter.
But if fills my heart with joy.
The test is case sensitive, but the actual response to `git config
commit.gpgSign` is equivalent to `git config commit.gppsign`
This allows changing git config values while lazygit is running (e.g. in a
different terminal tab, or even in lazygit's ":" shell prompt), and have them
take effect immediately, while still getting some benefit from caching them
while lazygit is in the foreground.
