patch 8.0.0983: unnecessary check for NULL pointer

Problem:    Unnecessary check for NULL pointer.
Solution:   Remove the NULL check in dialog_changed(), it already happens in
            dialog_msg(). (Ken Takata)

patch 8.0.0982: cannot use a terminal when 'encoding' is non-utf8 mul…

…ti-byte

Problem:    When 'encoding' is set to a multi-byte encoding other than utf-8
            the characters from ther terminal are messed up.
Solution:   Convert displayed text from utf-8 to 'encoding' for MS-Windows.
            (Yasuhiro Matsumoto, close vim#2000)

patch 8.0.0981: cursor in terminal window blinks by default

Problem:    Cursor in terminal window blinks by default, while in a real xterm
            it does not blink, unless the -bc argument is used.
Solution:   Do not use a blinking cursor by default.

patch 8.0.0980: Coverity warning for failing to open /dev/null

Problem:    Coverity warning for failing to open /dev/null.
Solution:   When /dev/null can't be opened exit the child.

patch 8.0.0979: terminal noblock test fails on MS-Windows

Problem:    Terminal noblock test fails on MS-Windows. (Christian Brabandt)
Solution:   Ignore empty line below "done".

patch 8.0.0978: writing to terminal job is not tested

Problem:    Writing to terminal job is not tested.
Solution:   Add a test.

patch 8.0.0977: cannot send lines to a terminal job on MS-Windows

Problem:    Cannot send lines to a terminal job on MS-Windows.
Solution:   Set jv_in_buf.  Command doesn't get EOF yet though.

patch 8.0.0976: cannot send lines to a terminal job

Problem:    Cannot send lines to a terminal job.
Solution:   Make [range]terminal send selected lines to the job.
            Use ++rows and ++cols for the terminal size.

patch 8.0.0975: using freed memory when setting 'backspace'

Problem:    Using freed memory when setting 'backspace'.
Solution:   When changing oldval also change origval.

patch 8.0.0974: resetting a string option does not trigger OptionSet

Problem:    Resetting a string option does not trigger OptionSet. (Rick Howe)
Solution:   Set the origval.