Fix the '--bundle-dup-excludes' flag and add '--bundle-dup-max-dups'

Now the default output prints out how many more you get:

   Duplicate classes and/or resources detected in artifacts: (u'commons-beanutils-commons-beanutils-1.7.0.jar', u'commons-beanutils-commons-beanutils-core-1.8.0.jar')
                        org/apache/commons/beanutils/BeanAccessLanguageException.class
                        org/apache/commons/beanutils/converters/URLConverter.class
                        org/apache/commons/beanutils/locale/converters/IntegerLocaleConverter.class
                        org/apache/commons/beanutils/converters/CharacterArrayConverter.class
                        org/apache/commons/beanutils/MethodUtils.class
                        org/apache/commons/beanutils/converters/BooleanConverter.class
                        org/apache/commons/beanutils/converters/ClassConverter.class
                        org/apache/commons/beanutils/DynaBean.class
                        org/apache/commons/beanutils/converters/BooleanArrayConverter.class
                        org/apache/commons/beanutils/Converter.class
                        ... 123 more ...

Testing Done:
I've got a lot of duplicate classes on the classpath to sort out...

devpants goal bundle <target> --bundle-dup-max-dups=50 --bundle-dup-excludes=dependencies,license,notice,.DS_Store,notice.txt,cmdline.arg.info.txt.1,license.txt,org.apache.hadoop.fs.FileSystem,BCKEY.DSA,BCKEY.SF,ASL2.0,javax.servlet.ServletContainerInitializer,about.html

Bugs closed: 332

Reviewed at https://rbcommons.com/s/twitter/r/656/