Added requirement for checking invalid file input for inclusion.
Refactoring out similar features from MessagesCentral and future
XPathCentral
Refactored MessagesCentral based on ResourceCentral
Basic copy from MessagesCentral modified for reading xpath.properties

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Moving enum closer to XPathCentral

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Added known prefixes.

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Added method for collection all values for a given prefix.

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Changed @<something>@ by {0}

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Refatored enum to have an interface, make tests easier

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Added comment about test keys
Added xpath.test entries for testing.

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Behaviour captured

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
null check ok.

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Added method getAvailableKeys() for XPathCentral

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Added new method tests

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Clean up

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Added wrapper method for getAllAvailableKeys()

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
cannot guarantee that array will be returned sorted.

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Passes all tests

OPEN - task 4: Put all XPath on an external file 
http://github.com/fgka/senac-auditing/issues/issue/4
Clean up