Merge pull request #1760 from StefanScherer/windows-programfiles-docker-cli-plugins

Search Windows CLI plugins also in ProgramFiles

cli-plugins/manager/manager_windows.go

@@ -7,4 +7,5 @@ import (
 
 var defaultSystemPluginDirs = []string{
 	filepath.Join(os.Getenv("ProgramData"), "Docker", "cli-plugins"),
+	filepath.Join(os.Getenv("ProgramFiles"), "Docker", "cli-plugins"),
 }

docs/extend/cli_plugins.md

@@ -111,7 +111,8 @@ the `/usr/local/lib` or `/usr/local/libexec` equivalents but packages
 should not do so.
 
 Plugins distributed on Windows for system wide installation should be
-installed in `%PROGRAMDATA%\Docker\cli-plugins`.
+installed in either `%ProgramData%\Docker\cli-plugins` or
+`%ProgramFiles%\Docker\cli-plugins`.
 
 User's may on all systems install plugins into `~/.docker/cli-plugins`.