add eclipse support to the gradle script and ignore special eclipse directories

.gitignore

@@ -22,3 +22,5 @@ target/
 .classpath
 .project
 test262
+bin/
+.settings/

build.gradle

@@ -1,5 +1,6 @@
 apply plugin: 'java'
 apply plugin: 'idea'
+apply plugin: 'eclipse'
 apply plugin: 'maven-publish'
 apply plugin: 'jacoco'
 apply plugin: 'distribution'