patch 8.0.1418: no test for expanding backticks

Problem:    No test for expanding backticks.
Solution:   Add a test. (Dominique Pelle, closes vim#2479)

patch 8.0.1417: test doesn't search for a sentence

Problem:    Test doesn't search for a sentence. Still fails when searching for
            start of sentence. (Dominique Pelle)
Solution:   Add paren. Check for MAXCOL in dec().

patch 8.0.1416: crash when searching for a sentence

Problem:    Crash when searching for a sentence.
Solution:   Return NUL when getting character at MAXCOL. (closes vim#2468)

patch 8.0.1415: warning for unused function without timers feature

Problem:    Warning for unused function without timers feature.
Solution:   Add #ifdef. (John Marriott)

patch 8.0.1414: accessing freed memory in :lfile.

Problem:    Accessing freed memory in :lfile.
Solution:   Get the current window after executing autocommands. (Yegappan
            Lakshmanan, closes vim#2473)

patch 8.0.1413: accessing freed memory in :cbuffer

Problem:    Accessing freed memory in :cbuffer.
Solution:   Get quickfix list after executing autocmds. (closes vim#2470)

patch 8.0.1412: using free memory using setloclist()

Problem:    Using free memory using setloclist(). (Dominique Pelle)
Solution:   Mark location list context as still in use when needed. (Yegappan
            Lakshmanan, closes vim#2462)

patch 8.0.1411: reading invalid memory with CTRL-W :

Problem:    Reading invalid memory with CTRL-W :.
Solution:   Correct the command characters. (closes vim#2469)

patch 8.0.1410: hang when using count() with an empty string

Problem:    Hang when using count() with an empty string.
Solution:   Return zero for an empty string. (Dominique Pelle, closes vim#2465)

patch 8.0.1409: buffer overflow in :tags command

Problem:    Buffer overflow in :tags command.
Solution:   Use vim_snprintf(). (Dominique Pelle, closes vim#2471, closes vim#2475)
            Add a test.