patch 8.0.0628: cursor disappears after silent mapping

Problem:    Cursor disappears after silent mapping. (Ramel Eshed)
Solution:   Do restore the cursor when it was changed, but don't change it in
            the first place for a silent mapping.

patch 8.0.0627: "gn" selects only one character with 'nowrapscan'

Problem:    When 'wrapscan' is off "gn" does not select the whole pattern when
            it's the last one in the text. (KeyboardFire)
Solution:   Check if the search fails. (Christian Brabandt, closes vim#1683)

patch 8.0.0626: in the GUI the cursor may flicker

Problem:    In the GUI the cursor may flicker.
Solution:   Check the cmd_silent flag before updating the cursor shape.
            (Hirohito Higashi, closes vim#1637)

patch 8.0.0625: shellescape() always escapes a newline

Problem:    shellescape() always escapes a newline, which does not work with
            some shells. (Harm te Hennepe)
Solution:   Only escape a newline when the "special" argument is non-zero.
            (Christian Brabandt, closes vim#1590)

patch 8.0.0624: warning for unused variable in tiny build

Problem:    Warning for unused variable in tiny build. (Tony Mechelynck)
Solution:   Add an #ifdef.

patch 8.0.0623: error for invalid regexp is not very informative

Problem:    The message "Invalid range" is used for multiple errors.
Solution:   Add two more specific error messages. (Itchyny, Ken Hamada)

patch 8.0.0622: selecting quoted text fails with 'selection' "exclusive"

Problem:    Using a text object to select quoted text fails when 'selection'
            is set to "exclusive". (Guraga)
Solution:   Swap cursor and visual start position. (Christian Brabandt,
            closes vim#1687)

patch 8.0.0621: :stag does not respect 'switchbuf'

Problem:    The ":stag" command does not respect 'switchbuf'.
Solution:   Check 'switchbuf' for tag commands that may open a new window.
            (Ingo Karkat, closes vim#1681)  Define macros for the return values
            of getfile().

patch 8.0.0620: checking for HAVE_GTK_MULTIHEAD is not needed

Problem:    Since we only support GTK versions that have it, the ckeck for
            HAVE_GTK_MULTIHEAD is no longer needed.
Solution:   Remove HAVE_GTK_MULTIHEAD. (Kazunobu Kuriyama)

patch 8.0.0619: GUI gets stuck if timer uses feedkeys()

Problem:    In the GUI, when a timer uses feedkeys(), it still waits for an
            event. (Raymond Ko)
Solution:   Check tb_change_cnt in one more place.