Move distributed static/ folder to dist/web/

Move the target folder for the built web interface to dist/web/ instead
of static/.  This better follows the norm for npm packages to include
built files in the dist/ folder and also allows putting other built
files into that folder in the future.

.gitignore

@@ -46,10 +46,6 @@ static/export
 saves
 /temp/
 
-# Web build
-/packages/master/static
-/plugins/*/static
-
 # IDE
 .idea/
 .vs/