introduce new logical validators any, all

closes #2 by introducing new logical operation validators instead
of the Validator::and/or methods. Use case:
// and
validate(someString, all(not(isNullOrEmptyString()), hasLength(5)));
// or
validate(obj, any(nullValue(), equalTo(other)));
update readme to use all/any
add javadoc for all/any
update gradle version to 0.2
update version numbers in readme
Merge branch 'master' of github.com:SakeSushiBig/validcool