[el-dev] Moving to a minimum of Java 11

[Mark Thomas <markt@xxxxxxxxxx>]

Hi all,

The Jakarta 10 Platform spec is moving to a minimum Java version of Java 
11. We can remain on an earlier Java version if we want to but I plan to 
move the EL API project to Java 11 shortly for the following reasons:

1. We can provide additional, useful information when deprecating the
   use of FeatureDescriptor and other methods from the Java Beans API.

2. We are required to include a module-info.class and adding that is
   simpler with a minimum of Java 9 (and Java 9 and 10 are no longer
   supported).

I am going to start work on this shortly, so if there are any objections 
please speak up so we can discuss them.

Mark