minor fixes
code improvements
code cleanups
code cleanups
XML and cleanups

- ADD: abstract XML framework
- CHG: code cleanups
xml wrappers

- ADD: SelectNodes() methods to IXmlNode
- ADD: Attributes() method to IXmlElement
- ADD: Nodes() method to IXmlContainer
- ADD: first implementations based on "old skool" XmlNode types and on
the other hand based on LINQ
xml wrappers

- ADD: IXmlContainer is a sequence of IXmlNode elements now
- ADD: ToString() method for LINQ based _XmlObject class
- ADD: more supported types for _XmlNode.CreateByNode() method
xml wrappers

- ADD: LocalName properties to IXmlAttribute and IXmlElement interfaces
- ADD: Elements() method to IXmlContainer
- ADD: Root property to IXmlDocument
- ADD: "this" property alias for SelectElements() method of IXmlNode
- FIX: added XmlDocumentFactory to other projects
- ADD: ToString() methods for returing OuterXml
- CHG: code cleanups and improvements
added NamespaceUri property to IXmlObject
tests and cleanups

- ADD: started to implement test projects
- CHG: code cleanups
added first NUnit based tests
Tests and CryptoRandom

- CHG: improved and extended tests
- CHG: own Assert.AreSame() methods
- UPD: factory methods of CryptoRandom
code cleanups and improvements