Visit all components of dotted library name. Fixes #109.

test/whitespace/directives.unit

Index: test/whitespace/directives.unit
diff --git a/test/whitespace/directives.unit b/test/whitespace/directives.unit
index aae0ce45cf18134063eb65ac895addf62eccfb97..a81dc25d2a774b1f8e3daa4f5d78cd3af75492e2 100644
--- a/test/whitespace/directives.unit
+++ b/test/whitespace/directives.unit
@@ -45,4 +45,8 @@ part of foo;
 >>> long part of does not wrap
 part of some_very_long_library_name_that_wraps;
 <<<
-part of some_very_long_library_name_that_wraps;
+part of some_very_long_library_name_that_wraps;
+>>> no spaces between library identifiers
+library    a .  b   . c;
+<<<
+library a.b.c;