RFR: JDK-8215516: Move JavadocTester to a named package

[Jonathan Gibbons]

Please review a test-only change to move JavadocTester from the unnamed 
package to a new, named package.

The name of the new package is "javadoc.tester.*". A number of 
alternatives were considered (javadoc.*, test.javadoc.*, 
javadoc.test.lib.*, etc)  javadoc.tester.* seemed the least bad. In 
addition, the location of the library was moved up a level, to allow for 
more javadoc-related test library classes to be added going forward.

Although conceptually simple, this does affect all tests that refer to 
it. There are up to 4 implications for each test.

1. Update the @library tag for the new location
2. Update the @build tag
3. Add an import for JavadocTester (and cleanup some other library 
imports, for toolbox classes)
4. For some tests, update the @Test methods to be public

Most (but not all) of the preceding changes were done by script and/or 
IDE. Some outlier cases were done manually, when checking that all tests 
still passed.

One test, TestOrdering.java, required bigger changes, to change static 
nested classes to inner classes, to utilize access to protected methods.

In TestRedirectLinks.java, there is a single-line, unrelated change to 
disconnect an HttpURLConnection, to help prevent test timeouts.

Finally, in JavadocTester itself, the declaration for the @Test type was 
made public.

There is no change to the functionality of any of the affected tests. 
After from the move, there are no other refactorings of JavadocTester at 
this time.

JBS: https://bugs.openjdk.java.net/browse/JDK-8215516
Webrev: http://cr.openjdk.java.net/~jjg/8215516/webrev.00/

-- Jon