minor: add JSR305CheckstylePlugin to list of known checkstyle extensions
minor: add JSR305CheckstylePlugin to list of known checkstyle extensions

rnveach/checkstyle,romani/checkstyle,romani/checkstyle,rnveach/checkstyle,checkstyle/checkstyle,liscju/checkstyle,sabaka/checkstyle,romani/checkstyle,rnveach/checkstyle,romani/checkstyle,jochenvdv/checkstyle,rnveach/checkstyle,rnveach/checkstyle,jochenvdv/checkstyle,sabaka/checkstyle,jonmbake/checkstyle,checkstyle/checkstyle,jochenvdv/checkstyle,checkstyle/checkstyle,romani/checkstyle,checkstyle/checkstyle,liscju/checkstyle,romani/checkstyle,sabaka/checkstyle,checkstyle/checkstyle,liscju/checkstyle,jonmbake/checkstyle,jonmbake/checkstyle,rnveach/checkstyle,checkstyle/checkstyle