[Kst] kst2 datasource API comments

[Peter Kümmel]

nicolas.brisset at free.fr wrote:
> - I find the ASCII datasource pretty complex.
> It's hard not to get lost between the AsciiSource (derived from Kst::DataSource), Ascii::Config and AsciiPlugin (derived from Kst::DataSourcePluginInterface) classes. In the .cpp you get the expected ConfigWidgetAscii, which is no more in ascii.h than Ascii::Config. And I'm not even mentioning the fact that Ascii::Config has read but no write and that it mixes working with QSettings and the XML .kst file. Or count the number of times there is the string "Comment Delimiters": 6, qnd it's only counting the management of settings! Phew! I don't remember it being so complex when I improved it a bit a few years ago. I wonder if I wouldn't just have given up if it had been as complex as today! And by the way, I think that Peter forgot to save properly the "use dot" property in the XML when he introduced it, which is probably a sign that it needs some refactoring. But that's actually more the ASCII datasource itself than the Kst::DataSource class in itself, which I guess is rathe
r good news :-)

I've cleaned up the ascii.cpp code: splitted into more files,
removed the duplicates of key and tag names, and hopefully made
it more readable.

Maybe it is also possible to simplify datasource.h

Peter