This prevents void-variable +popup-buffer-mode-map errors that occur in
some hard to reproduce scenarios.
Also ensures that window-persistent-parameters is being restored when
+popup-mode is disabled.
load!'s first argument is no longer a symbol (that will cause
void-variable errors now) to save on unnecessary interning and simplify
compile-time logic. It accepts any valid form that evaluates to a string
now.
If you use load!, you need to change its argument to a string!
e.g. (load! +my-module) => (load! "+my-module")
(autosave . CDR)
This parameter determines what to do with modified buffers in closing
popup windows. CDR can be a t, 'ignore, a function or nil.
+ If t, no prompts. Just save them automatically (if they're
file-visiting buffers).
+ If 'ignore, no prompts, no saving. Just silently kill it.
+ If nil (the default), prompt the user what to do if the buffer is
file-visiting and modified.
+ If a function, the return value must return one of the other values.
It takes two arguments: the popup window and buffer.
