Issue 263 ; adding @since tags

git-svn-id: http://piccolo2d.googlecode.com/svn/piccolo2d.java/trunk@1270 aadc08cf-1350-0410-9b51-cf97fce99a1b
Issue 262 ; adding getPropertyChangeListeners and getPropertyChangeListeners(String) methods

git-svn-id: http://piccolo2d.googlecode.com/svn/piccolo2d.java/trunk@1271 aadc08cf-1350-0410-9b51-cf97fce99a1b
Issue 260 ; applying patch from jlessner@

git-svn-id: http://piccolo2d.googlecode.com/svn/piccolo2d.java/trunk@1272 aadc08cf-1350-0410-9b51-cf97fce99a1b
Issue 261 ; applying patch from jlessner@

git-svn-id: http://piccolo2d.googlecode.com/svn/piccolo2d.java/trunk@1273 aadc08cf-1350-0410-9b51-cf97fce99a1b