updated to 7.4.052

updated to 7.4.052

7.4.028  equivalence classes are not working for multi-byte characters
7.4.029  an error in a pattern is reported twice
7.4.030  the -mno-cygwin argument is no longer supported by Cygwin
7.4.031  ":diffoff!" resets options even when 'diff' is not set
7.4.032  NFA engine does not match the NUL character
7.4.033  if terminal has 20 lines test 92 and 93 overwrite input file
7.4.034  using "p" in Visual block mode only changes the first line
7.4.035  MS-Windows: mouse pointer flickers when going to Normal mode
7.4.036  NFA engine does not capture group correctly when using \@>
7.4.037  "\ze" in a sub-pattern does set the end of the match
7.4.038  Using "zw" and "zg" when 'spell' is off give confusing error
7.4.039  MS-Windows: < MSCV10 can't handle symlinks to a directory
7.4.040  error on exit when variable holds reference to a script scope
7.4.041  Visual selection does not remain after being copied over
7.4.042  after ":setlocal" 'spell'/'spellang' :spelldump doesn't work
7.4.043  VMS can't handle long function names
7.4.044  can't build with old MSVC
7.4.045  substitute() has a problem with pattern starting with "\ze".
7.4.046  can't use Tcl 8.6
7.4.047  input() does not work in a function invoked by a mapping
7.4.048  recent clang version complains about -fno-strength-reduce
7.4.049  in Ex mode substitute prompt is wrong with line numbers
7.4.050  "gn" may select too much when there are two matching lines
7.4.051  syntax highlighting a Yaml file causes a crash
7.4.052  cursor may end up in the wrong position when auto-formatting