[JAVA-1453] Applied 3.0 updated documentation to 2.13 code for the com.mongodb package

Used a combination of the same checkstyle rules that we use in 3.x and IntelliJ's inspections to track down missing public class/method documentation and apply changes from the 3.x branch.  Deprecated methods are not included, although if javadoc already existed for these methods/classes it has been retained.
We had a checkstyle file, but checkstyle was never enabled in the build.  I disabled all the checks that were failing (most of them) and added the Javadoc checks,  This is still not enabled in the build (there's no way to turn off the check for deprecated methods and classes) but it gives us checkstyle settings which are close to being enabled should we want to.