Change jre and jdk booleans to a single string

Dan raised the comment in the previous patch set that it doesn't make
sense to provide two options and four states when there are really only
two possibilities; install the jre or the jdk.

This change removes the jdk and jre class parameters and replaces them
with a single distribution parameters.

manifests/init.pp

@@ -12,33 +12,31 @@
 #
 # [Remember: No empty lines between comments and class definition]
 class java(
-  $jre = false,
-  $jdk = true,
-  $version='1.6.0_25-fcs'
+  $distribution = 'jdk',
+  $version      = 'installed'
 ) {
 
   # Cannot pass anonymous arrays to functions in 2.6.8
-  $v_true_false = [ '^true$', '^false$' ]
+  $v_distribution = [ '^jre$', '^jdk$' ]
   # Must compare string values, not booleans.
-  validate_re("$jre", $v_true_false)
-  validate_re("$jdk", $v_true_false)
   validate_re($version, '^[._0-9a-zA-Z:-]+$')
+  validate_re($distribution, $v_distribution)
 
-  $jre_real     = $jre
-  $jdk_real     = $jdk
-  $version_real = $version
+  $version_real      = $version
+  $distribution_real = $distribution
 
-  if $jre_real {
-    class { 'java::jre_package':
-      version => $version_real,
-      stage   => 'runtime',
+  case $distribution_real {
+    jre: {
+      class { 'java::jre_package':
+        version => $version_real,
+        stage   => 'runtime',
+      }
     }
-  }
-
-  if $jdk_real {
-    class { 'java::jdk_package':
-      version => $version_real,
-      stage   => 'runtime',
+    jdk: {
+      class { 'java::jdk_package':
+        version => $version_real,
+        stage   => 'runtime',
+      }
     }
   }