tighten up perl ignores - these files should only exist in the repository root

Perl.gitignore

@@ -1,5 +1,5 @@
-blib/
-.build/
+/blib/
+/.build/
 _build/
 cover_db/
 inc/
@@ -7,10 +7,10 @@ Build
 !Build/
 Build.bat
 .last_cover_stats
-Makefile
-Makefile.old
-MANIFEST.bak
-META.yml
-MYMETA.yml
+/Makefile
+/Makefile.old
+/MANIFEST.bak
+/META.yml
+/MYMETA.yml
 nytprof.out
-pm_to_blib
+/pm_to_blib