(MODULES-1570) java_patch_level fact

Uses the `java_version` fact and gets the patch level by splitting after `_`

This would be useful if you want to make sure you're not accidentally downgrading the version of Java to a lower patch level (I've noticed some package managers don't notice this too well)

lib/facter/java_patch_level.rb

@@ -0,0 +1,22 @@
+# Fact: java_patch_level
+#
+# Purpose: get Java's patch level
+#
+# Resolution:
+#   Uses java_version fact splits on the patch number (after _)
+#
+# Caveats:
+#   none
+#
+# Notes:
+#   None
+Facter.add(:java_patch_level) do
+  setcode do
+    java_version = Facter.value(:java_version)
+    if java_version.nil?
+      "JAVA_NOT_INSTALLED"
+    else
+      java_patch_level = java_version.strip.split('_')[1]
+    end
+  end
+end