Use Jar Classloading to complete import statements.

Examples:
groovy:000> import
groovy:000> import j
groovy:000> import java.
groovy:000> import java.net.
groovy:000> import static java.net.



Also complete Classnames for preimported and imported classes

Example:
groovy:000> Sys<tab>

Before: no completion
Afer: completes to System  (from java.lang.System)

Also:
groovy:000> import java.awt.*
groovy:000> Sha<tab>

now completes to "Shape"

As well imported statics:
groovy:000> import static java.lang.Math.*
===> [import static java.lang.Math.*]
groovy:000> ma<tab>

now completes to "max("