SciDAVis - Improvements SVN-temp

- Fixes bug in bool Graph::focusNextPrevChild () function.

- Rewritten "IsBigEndian()" function in importOPJ class in a more portable way.
- Improved the import of tables horizontal header.
- Improved ExpDecayDialog and add/remove CurvesDialog.
- The resize of a text marker in a 2D plot now modifies the font of the text accordingly.
- Improved storing/restoring to/from files for the ImageMarker class.
- Fixed cloning of 2D plots.
- Improved exporting of plots to image format files.
- Fixed bugs due to mixing of QwtPlotCurve and QwtPlotItem in 2D plots.

- add matrix import from OPJ Files (v.7.5)

- added display of Delta_x/y in RangeSelectorTool

- small improvement to RangeSelectorTool

- fixed invalid/undefined data type 'byte'

- Fixed crash when double-clicking on a selected Line or Text Marker.
- Tried to improve tab focus on 2D plot markers, still buggy!

add spreadsheet's properties import from OPJ(v.7.5): labels, formulas, formats, widths; hidden and loose datasets

- Fixed 2D plot curves context menu.

- Fixed crash when removing curves from 2D plots.
- Renamed some 2D plots export functions for a more unitary naming scheme.