Fix eclipse/README.txt wrt requestfactory-apt

Also move the section to after the gwt-user project has been imported
and requestfactory-apt.jar has been built with Ant, and add a note for
those working on changing the behavior of requestfactory-apt.

Change-Id: I0ce0d16361c67dff3f8e7e15d4c7db7a61700da0
1 file changed