Append / to directories in Glob results

This makes it easy for users of Glob to detect whether the match is a
file or directory. Doing the check at this level means that the filelist
file used as a dependency will be updated if a directory is replaced
with a file of the same name, or vice versa.

Change-Id: I79ebba39327218bcdcf50b393498306119de9d6c
diff --git a/singleton_ctx.go b/singleton_ctx.go
index 28fecf0..bbfce00 100644
--- a/singleton_ctx.go
+++ b/singleton_ctx.go
@@ -65,10 +65,12 @@
 
 	AddNinjaFileDeps(deps ...string)
 
-	// GlobWithDeps returns a list of files that match the specified pattern but do not match any
-	// of the patterns in excludes.  It also adds efficient dependencies to rerun the primary
-	// builder whenever a file matching the pattern as added or removed, without rerunning if a
-	// file that does not match the pattern is added to a searched directory.
+	// GlobWithDeps returns a list of files and directories that match the
+	// specified pattern but do not match any of the patterns in excludes.
+	// Any directories will have a '/' suffix. It also adds efficient
+	// dependencies to rerun the primary builder whenever a file matching
+	// the pattern as added or removed, without rerunning if a file that
+	// does not match the pattern is added to a searched directory.
 	GlobWithDeps(pattern string, excludes []string) ([]string, error)
 
 	Fs() pathtools.FileSystem