Adding instructions to ensure that eclipse is in 1.5 compliance mode.

git-svn-id: https://google-web-toolkit.googlecode.com/svn/releases/1.6@4297 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/eclipse/README.txt b/eclipse/README.txt
index 62e1834..54955ca 100644
--- a/eclipse/README.txt
+++ b/eclipse/README.txt
@@ -67,6 +67,11 @@
 
 Third, within a category/visibility combination, members should be sorted
 alphabetically.
+ 
+
+------------ Compiler settings ------------
+Window->Preferences->Java->Compiler
+Set the compiler compliance level to 1.5.
 
 == Checkstyle ==