Continuous energies changes started

1) created new fundamental type xmi_energy_continuous
2) old xmi_energy renamed as xmi_energy_discrete
3) XML DTD updated
4) xml read/write functions updated
5) all fortran code updated, some new functions (module procedures)
6) Possible Ebel bug detected, needs confirmation from Armando
7) xmi_validate_input now returns info in function result on where
validation failed -> renamed macros, later versions should specify even
more!
Continuous energies support added to xmi_main

Untested, but no real problems expected...
More work: new xmi_energy_continuous support being added to GUI

...incomplete
Everything seems fine: last_energy, xmimsim etc
Fortran solid angle code now ok with continuous energies
Fortran main: small bugfix

Code was unpredictable if source would not be in first layer
Fortified energy modification dialog
Bugfix in error handling input page GUI
Ebel dialog first version ready

Error handling needs to improve a lot still
Backwards compatibility ensured with old Gtk2 versions

Version bump

Ebel tool works but needs additional error checking... crashes very very
easily!
Dropped support for GTK Extra 2

No need anymore since version 3 also works on windows
More improvements

Ebel interface cleaned up and added some interesting new features such
as export to ascii and export to image.

xmi_tube_ebel now returns continuous energy intensities PER interval!
Move to Laszlo's and Bruno's model for the continuous intervals

Several bugfixes in the GUI
Bugfixes and minor improvements

Fortified support for continuous intervals
Layer, compound and energy dialogs now have grab_default for the Ok
button, which was a longstanding request from Matthias Alfeld