Advanced Aliases

This is somehow a generalizing of the bugs: 85 (context aliases) and 62 (primitives as attributes)

1. Context Alias: alias(String element, Class context, Class type)
2. Adv Context Alias: alias(String element, Class context, String fieldName)

Attribute Aliases

3. aliasAttribute(String attr, Class type)
4. Context Alias: aliasAttribute(String attr, Class context, Class type)
5. Adv Context Alias: aliasAttribute(String attr, Class context, String fieldName)

Attribute Aliases should of course only be possible if a basic converter is present.
It would be needed to abstract Basic Converters from the HierarchicalStreamWriter/Reader and only expose a to- and fromString method, while the rest is framework. Basically it would mean that there is a Converter and a BasicConverter interface.

Last but not least of bug 50 is solved, one would be able to store all this aliases in a configuration file.