New Java Plug-In needs to add current JRE to available JREs in more situations

Because the installer does not properly refresh deployment.properties, and also somewhat because the list of available JREs for the Java Plug-In in the Java Control Panel is not maintainable (see 6606278, 6606282), it is necessary for a workaround to be placed in the new Java Plug-In so it will find the current JRE it is running on top of in more situations.

The code in JVMManager.processPluginJavaInfo() needs to be changed to add the current JRE it is running on top of in more situations. Currently it only adds it if deployment.properties does not exist, or contains no listed JREs. It needs to be changed to add it in all situations *unless*:
  - there is a version of the JRE in deployment.properties matching the version it is running on top of, *and*
  - that JRE actually exists.

This workaround will have the side-effect that it will not be possible to use the Java Control Panel to remove the current JRE as an available JRE for the new Java Plug-In. However the alternative, which is that the end user must run the Java Control Panel once after installation in order to get the new plug-in to notice the availability of the current JRE (assuming deployment.properties already exists and has at least one JRE listed for the plug-in), is not acceptable.