Following JavaDoc has format errors.

• duplicate "/**"
  https://github.com/beanvalidation/beanvalidation-api/blob/master/src/main/java/javax/validation/executable/ExecutableType.java#L53

• missing dot in title line.
  https://github.com/beanvalidation/beanvalidation-api/blob/master/src/main/java/javax/validation/constraints/Digits.java#L27

• p tag is missing before "Supported types are:" (
  The format is not unified as compared with other files)
  https://github.com/beanvalidation/beanvalidation-api/blob/master/src/main/java/javax/validation/constraints/NotEmpty.java#L27
  https://github.com/beanvalidation/beanvalidation-api/blob/master/src/main/java/javax/validation/constraints/Digits.java#L28