patch 8.0.0596: crash when complete() called after complete_add()

Problem:    Crash when complete() is called after complete_add() in
            'completefunc'. (Lifepillar)
Solution:   Bail out if compl_pattern is NULL. (closes vim#1668)
            Also avoid using freed memory.

patch 8.0.0595: Coverity warning for not checking return value

Problem:    Coverity warning for not checking return value of dict_add().
Solution:   Check the return value for FAIL.

patch 8.0.0594: build failure when windows feature is missing

Problem:    Build failure when windows feature is missing.
Solution:   Add #ifdef.

patch 8.0.0593: duplication of code for adding a list or dict return …

…value

Problem:    Duplication of code for adding a list or dict return value.
Solution:   Add rettv_dict_set() and rettv_list_set(). (Yegappan Lakshmanan)

patch 8.0.0592: if a job writes to a buffer screen is not updated

Problem:    If a job writes to a buffer and the user is typing a command, the
            screen isn't updated. When a message is displayed the changed
            buffer may cause it to be cleared. (Ramel Eshed)
Solution:   Update the screen and then the command line if the screen didn't
            scroll. Avoid inserting screen lines, as it clears any message.
            Update the status line when the buffer changed.

patch 8.0.0591: changes to eval functionality not documented

Problem:    Changes to eval functionality not documented.
Solution:   Include all the changes.

patch 8.0.0590: cannot add a context to locations

Problem:    Cannot add a context to locations.
Solution:   Add the "context" entry in location entries. (Yegappan Lakshmanan,
            closes vim#1012)

patch 8.0.0589: :simalt still does not work

Problem:    :simalt still does not work.
Solution:   Use K_NOP instead of K_IGNORE. (Christian Brabandt)

patch 8.0.0588: job_stop() often assumes the channel will be closed

Problem:    job_stop() often assumes the channel will be closed, while the job
            may not actually be stopped. (Martin Gammelsæter)
Solution:   Only assume the job stops on "kill".  Don't send a signal if the
            job has already ended. (closes vim#1632)

patch 8.0.0587: configure check for return value of tgetent skipped

Problem:    Configure check for return value of tgetent is skipped.
Solution:   Always perform the check. (Marvin Schmidt, closes vim#1664)