Add sanity checks for package.* dirs

manifests/keywords.pp

 define gentoo::keywords ($source="", $ensure=present) {
-    file { "gentoo_keywords_${name}":
-        path    => "/etc/portage/package.keywords/${name}",
-        source  => "${source}",
-        ensure  => $ensure,
+    file {
+        "gentoo_keywords_${name}":
+            path    => "/etc/portage/package.keywords/${name}",
+            source  => "${source}",
+            ensure  => $ensure,
+            require => File["/etc/portage/package.keywords"];
+        "/etc/portage/package.keywords":
+            ensure  => directory;
     }
 }

manifests/mask.pp

 define gentoo::mask ($source="", $ensure=present) {
-    file { "gentoo_mask_${name}":
-        path    => "/etc/portage/package.mask/${name}",
-        source  => "${source}",
-        ensure  => $ensure,
+    file {
+        "gentoo_mask_${name}":
+            path    => "/etc/portage/package.mask/${name}",
+            source  => "${source}",
+            ensure  => $ensure,
+            require => File["/etc/portage/package.mask"];
+        "/etc/portage/package.mask":
+            ensure  => directory;
     }
 }

manifests/unmask.pp

 define gentoo::unmask ($source="", $ensure=present) {
-    file { "gentoo_unmask_${name}":
-        path    => "/etc/portage/package.unmask/${name}",
-        source  => "${source}",
-        ensure  => $ensure,
+    file {
+        "gentoo_unmask_${name}":
+            path    => "/etc/portage/package.unmask/${name}",
+            source  => "${source}",
+            ensure  => $ensure,
+            require => File["/etc/portage/package.unmask"];
+        "/etc/portage/package.unmask":
+            ensure  => directory;
     }
 }

manifests/use.pp

 define gentoo::use ($source="", $ensure=present) {
-    file { "gentoo_use_${name}":
-        path    => "/etc/portage/package.use/${name}",
-        source  => "${source}",
-        ensure  => $ensure,
+    file {
+        "gentoo_use_${name}":
+            path    => "/etc/portage/package.use/${name}",
+            source  => "${source}",
+            ensure  => $ensure,
+            require => File["/etc/portage/package.use"];
+        "/etc/portage/package.use":
+            ensure  => directory;
     }
 }