patch 8.0.0317: no test for setting 'guifont'

Problem:    No test for setting 'guifont'.
Solution:   Add a test for X11 GUIs. (Kazunobu Kuriyama)

patch 8.0.0316: :help z? does not work

Problem:    ":help z?" does not work. (Pavol Juhas)
Solution:   Remove exception for z?.

patch 8.0.0315: :help :[range] does not work

Problem:    ":help :[range]" does not work. (Tony Mechelynck)
Solution:   Translate to insert a backslash.

patch 8.0.0314: getcmd*() functions are not tested

Problem:    getcmdtype(), getcmdpos() and getcmdline() are not tested.
Solution:   Add tests. (Yegappan Lakshmanan)

patch 8.0.0313: not enough testing for GUI functionality

Problem:    Not enough testing for GUI functionality.
Solution:   Add tests for the GUI font. (Kazunobu Kuriyama)

patch 8.0.0312: failure when a channel receives a split json message

Problem:    When a json message arrives in pieces, the start is dropped and
            the decoding fails.
Solution:   Do not drop the start when it is still needed. (Kay Zheng)  Add a
            test.  Reset the timeout when something is received.

patch 8.0.0311: linebreak tests are old style

Problem:    Linebreak tests are old style.
Solution:   Turn the tests into new style. Share utility functions. (Ozaki
            Kiichi, closes vim#1444)

patch 8.0.0310: not enough testing for GUI functionality

Problem:    Not enough testing for GUI functionality.
Solution:   Add tests for v:windowid and getwinpos[xy](). (Kazunobu Kuriyama)

patch 8.0.0309: cannot use an empty key in json

Problem:    Cannot use an empty key in json.
Solution:   Allow for using an empty key.

patch 8.0.0308: 'runtimepath' not update correctly when using symboli…

…c link

Problem:    When using a symbolic link, the package path will not be inserted
            at the right position in 'runtimepath'. (Dugan Chen, Norio Takagi)
Solution:   Resolve symbolic links when finding the right position in
            'runtimepath'. (Hirohito Higashi)