bug#32610: Enhancement Request (Flyspell/Ispell): Customizing a NIL value for ispell-async-processp.

[Keith David Bershatsky]

Some users (such as myself) may desire to control whether a spelling subprocess 
runs all the time.  Flyspell does not work if a user purposefully sets 
ispell-async-processp to a nil value.

Step 1:

(require 'flyspell)

(setq ispell-program-name "/path/to/aspell")

(setq ispell-async-processp nil)

(turn-on-flyspell)

Step 2:  Switch to the *Messages* buffer and observe the error message:

Error enabling Flyspell mode:
(

@(#) International Ispell Version 3.1.20 (but really Aspell 0.60.6.1))

EXPECTATION:  It would be nice if a user could choose whether to run a separate 
process each time `aspell` is called, rather than running a subprocess all the 
time.

OBSERVATION:  It appears to me from a review of the code that some initial work 
has already been done to permit Flyspell and/or Ispell to work with 
ispell-async-processp having a nil value; however, additional modification of 
the code is needed.