Problem:    Cannot easily try out what codes various keys produce.
Solution:   Add a script to gather key code information, with an initial list
            of codes to compare with.

Problem:    Horizontal mouse scroll only works in the GUI.
Solution:   Make horizontal mouse scroll also work in a terminal.
            (Christopher Plewright, closes #11448)

Problem:    Informational message has an error message number.
Solution:   Use a message without an error number. (closes #11530)

Problem:    Mouse shape remains in op-pending mode after failed change.
Solution:   Reset finish_op and restore it. (closes #11545)

Problem:    A silent mapping may cause dots on the command line.
Solution:   Don't show dots for completion if they are not going to be removed
            again. (closes #11501)

Problem:    Using freed memory after SpellFileMissing autocmd uses bwipe.
Solution:   Bail out if the window no longer exists.

Problem:    Cannot get the currently showing mouse shape.
Solution:   Add getmouseshape().

Problem:    Preprocessor indenting is off.
Solution:   Adjust preprocessor indentation. (Ken Takata, closes #11546)

Problem:    Unnecessary nesting in makefile.
Solution:   Join "else" and "ifeq". (Ken Takata, closes #11547)

Problem:    Coverity warns for dead code.
Solution:   Remove the dead code.