fix javadoc doclint errors

[hrldcpr]

We get doclint errors when running ./gradlew javadoc, if we don't enable Xdoclint:none in build.gradle

Mostly it's just @param fields with no description—simplest would be to just delete them entirely.

Once this is working, remove the Xdoclint:none in build.gradle

[ghost]

Errors confirmed.
Just a quick question - is there any reason for Maven to be used as well for project build tasks when Gradle is used already? It is confusing to see pom.xml as well on the root of the project [the POM file can be generated by Gradle as a build step as far as I know].

[hrldcpr]

Yeah good question, there's no good reason, someone added Gradle at some point. I'm happy to switch to one or the other, as long as we can still do everything required for releasing (i.e. the instructions in CHANGING). Gradle certainly has less verbose config files. Made a new issue for this - #64

[blackdrag]

That was me I guess, since I am not a big fan of maven. I think I simply forgot to remove the maven parts completely.

[hrldcpr]

@blackdrag haha cool, yeah it seems better as far as I can tell, let's go all in!