This patch upgrades maven-checkstyle-plugin to the latest available
version, 2.17.
This is done in order to consume a fix for checkstyle wrongfully
reporting an error if the @return javadoc tag was used in an
annotation type, as it is in Guarded (line 36).
Note that checkstyle has removed the RedundantThrows check (see
discussion at https://github.com/checkstyle/checkstyle/issues/473),
so it was removed from the project's checkstyle.xml configuration.
The defacto style of the project requires Javadoc for public methods
only, but the checkstyle Javadoc check defaults to requiring them even
for private methods, generating 46 errors.
This patch sets the checkstyle Javadoc check's scope to public to clean
up the checkstyle report so it can be enabled in the CI.
If we wish to reset the check to a laxer scope, the aforementioned
errors should be fixed first.
PR #248 corrected all the long literals to use the upper case L
notation.
This patch finishes the job as per the discussion there, and adds a
checktysle check to ensure no code that introduces long literals with
lowercase l are introduced.
Allon Mureinik
Bruno P. Kinoshita
Benedikt Ritter
Gary D. Gregory
Phil Steitz
Niall Pemberton
Henri Yandell