Fix accessibility and other issues in the java.xml.bind module

The following files have accessibility issues which should be addressed:

jaxws/src/java.xml.bind/share/classes/javax/xml/bind/JAXBPermission.java
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/Marshaller.java
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/Unmarshaller.java
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/annotation/XmlNsForm.java
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/annotation/XmlType.java
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/annotation/adapters/package-info.java
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/annotation/package.html
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/attachment/AttachmentUnmarshaller.java
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/helpers/package-info.java
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/util/package-info.java


In addition, the following files are redundant, since they are shadowed by equivalent package-info.java files, and so these files can be removed.

jaxws/src/java.xml.bind/share/classes/javax/xml/bind/annotation/adapters/package.html
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/helpers/package.html
jaxws/src/java.xml.bind/share/classes/javax/xml/bind/util/package.html