Problem:    Undo message delays screen update for CTRL-O u.
Solution:   Add smsg_attr_keep(). (closes #3125)

Problem:    Translators don't always understand the maintainer message.
Solution:   Add a comment that ends up in the generated po file. (Christian
            Brabandt, closes #3037)

Problem:    All tab stops are the same.
Solution:   Add the variable tabstop feature. (Christian Brabandt,
            closes #2711)

Problem:    In terminal window, typing : at more prompt, inserts ':' instead
            of starting another Ex command.
Solution:   Add skip_term_loop and set it when putting ':' in the typeahead
            buffer.

Problem:    Cannot tell whether a register is being used for executing or
            recording.
Solution:   Add reg_executing() and reg_recording(). (Hirohito Higashi,
            closes #2745)  Rename the global variables for consistency.  Store
            the register name in reg_executing.

Problem:    Dialog messages are not translated.
Solution:   Add N_() and _() where needed. (Sergey Alyoshin)

Problem:    Condition always false, useless code.
Solution:   Remove the code. (Nikolai Pavlov, closes #2808)

Problem:    Clearing a pointer takes two lines.
Solution:   Add VIM_CLEAR() and replace vim_clear(). (Hirohito Higashi,
            closes #2629)

Problem:    Illegal memory access in del_bytes().
Solution:   Check for negative byte count. (Christian Brabandt, closes #2466)

Problem:    Slow redrawing with DirectX.
Solution:   Avoid calling gui_mch_flush() unnecessarily, especially when
            updating the cursor. (Ken Takata, closes #2560)