Documentation:
--------------
* converted from HTML 4.01 Transitional to XHTML 1.1 (reason: the website
uses already XHTML 1.0 Strict, and our page didn't validate as such, even
though on the website a link to the W3C markup validation service is
affixed)
* removed some misleading sentences
* referenced the source files of examples, so that they do not go out of
sync again
* clarified rationale section
Example files:
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* example 3 shows that stream extraction may expand the bitset
* minor improvements to all examples
[SVN r47389]
