Update javadoc and JRE emulation page to 2.6.1

The javadoc has been generated from the 2.6.1 tag with
I85170407b11e27e8c8ff5fb2db77c46936205db5 applied on top.
In addition, links in the JRE emulation page have all been
updated to link to Java SE 7 javadoc rather than Java SE 6,
given the addition of Java 7 APIs (AutoCloseable, Objects, etc.)

Change-Id: I0584920ccc76e20c2d008c3d9e973ee7dc88b3c6