vim: Import v8.1.0053

* 8.1.0053: first argument of 'completefunc' has inconsistent type
* 8.1.0052: when mapping to <Nop> times out the next mapping is skipped
* 8.1.0051: MS-Windows: missing #endif
* 8.1.0050: $VIM_TERMINAL is also set when not in a terminal window
* 8.1.0049: shell cannot tell running in a terminal window
* 8.1.0048: vim_str2nr() does not handle numbers close to the maximum
* 8.1.0047: no completion for :unlet $VAR
* 8.1.0046: loading a session file fails if 'winheight' is big
* 8.1.0045: popup test isn't run completely
* 8.1.0044: if a test function exists Vim this may go unnoticed
* 8.1.0043: ++bad argument of :edit does not work properly

Author: chrisbra

gitlog.txt

@@ -1 +1 @@
-* [8.1.0042](https://github.com/vim/vim/releases/tag/v8.1.0042): if omni completion opens a window Insert mode is stopped\n* [8.1.0041](https://github.com/vim/vim/releases/tag/v8.1.0041): attribute "width" missing from python window attribute list\n* [8.1.0040](https://github.com/vim/vim/releases/tag/v8.1.0040): warnings from 64-bit compiler
+* [8.1.0053](https://github.com/vim/vim/releases/tag/v8.1.0053): first argument of 'completefunc' has inconsistent type\n* [8.1.0052](https://github.com/vim/vim/releases/tag/v8.1.0052): when mapping to <Nop> times out the next mapping is skipped\n* [8.1.0051](https://github.com/vim/vim/releases/tag/v8.1.0051): MS-Windows: missing #endif\n* [8.1.0050](https://github.com/vim/vim/releases/tag/v8.1.0050): $VIM_TERMINAL is also set when not in a terminal window\n* [8.1.0049](https://github.com/vim/vim/releases/tag/v8.1.0049): shell cannot tell running in a terminal window\n* [8.1.0048](https://github.com/vim/vim/releases/tag/v8.1.0048): vim_str2nr() does not handle numbers close to the maximum\n* [8.1.0047](https://github.com/vim/vim/releases/tag/v8.1.0047): no completion for :unlet $VAR\n* [8.1.0046](https://github.com/vim/vim/releases/tag/v8.1.0046): loading a session file fails if 'winheight' is big\n* [8.1.0045](https://github.com/vim/vim/releases/tag/v8.1.0045): popup test isn't run completely\n* [8.1.0044](https://github.com/vim/vim/releases/tag/v8.1.0044): if a test function exists Vim this may go unnoticed\n* [8.1.0043](https://github.com/vim/vim/releases/tag/v8.1.0043): ++bad argument of :edit does not work properly