Added ability to get data (as strings) from file. Added aditional error check in constructor for empty xml document.
Added ability to get data (as strings) from file.
Added aditional error check in constructor for empty xml document.


git-svn-id: 1001b6e0dd469eaa302a741812f7f5d223cf35f7@607 ff5d1e40-2be0-497f-93bd-dc18237bd3c7

nexusformat/code,chrisemblhh/nexus,chrisemblhh/nexus,nexusformat/code,nexusformat/code,chrisemblhh/nexus,chrisemblhh/nexus,nexusformat/code,nexusformat/code,chrisemblhh/nexus