Version 0.18

+ Split Structure from Items with data. Structure now contains items'
structure without XmlNodes.
One DataRootItem created. Updated the whole project to work with this
change. (bugs still exist)
+ Created .dat file DataParser.
+ Created data Titles Selection Form/Dialog for axis' from .dat files
before the chart creation.
+ Loading properly the data from .dat files and graphical representation
of these data
in a chart by ZedGraph. Limited to 10 Y-Axis' values.
+ Proper error handling in each case of invalid data.
+ Updated ZedGraph library to the latest build (5.15).
+ Removed 4th number from Assembly Version. (Menu>About)