Remove overwrite prompt for windows make.bat
When building the docs on a Windows system with Bokeh's `make.bat` file (e.g. `make.bat html`), Windows unnecessarily prompts the user to overwrite existing files. Adding the option `/y` to the .bat-file's xcopy command will automatically overwrite those files.
Solves
@@ -38,7 +38,7 @@ if "%1" == "all" (
if "%1" == "html" (
%SPHINXBUILD% -b html %ALLSPHINXOPTS% %BUILDDIR%\html
- xcopy ..\bokeh\server\static %BUILDDIR%\html\static\ /s /e /h
+ xcopy ..\bokeh\server\static %BUILDDIR%\html\static\ /s /e /h /y
if errorlevel 1 exit /b 1
echo.
echo.Build finished. The HTML pages are in %BUILDDIR%/html.
