For a long javadoc required a set of sample api's ie. java source files that have all possible javac language constructs
and exercise all possible javadoc tags, and some amount of inlined html tags. This is required to characterize the
test coverage, verify HTML correctness and possibly consistent behavior wrt. html production and comparison.

This needs to be integrated as following:
1. clone jdk9/dev
2. create langtools/test/tools/javadoc/sampleapi
3. create a directory langtools/test/tools/javadoc/sampleapi/src
4. create langtools/test/tools/javadoc/sampleapi/SampleApi.java

SampleApi.java: is a jtreg style regression test and should do the following:
   a. build everything under src
   b. invoke sample api with the right flags and generate the javac sources
   c. invoke javadoc on the sources generated in step b., with all the necessary
       options in order to get maximum coverage,
       Note: invoke javadoc with -html4 and -html5 into two separate discrete directories, such
       that the output can be analyzed using a tool such as tidy.