Cut all trailing whitespace including funky unicode characters

[sadielbartholomew]

The AsciiDoc files, newly cleaned up as part of #387, still have trailing whitespace, including whitespace in the form of some funky unicode characters, e.g. U+00A0, which should be removed for code hygiene.

Suggested as part of abiding by style guides in #373 (comment). While the specific style guides are being debated, all (sensible ones) will advocate for no trailing whitespace, so this is not controversial and can be done immediately, and should be done as one, like with the first stage clean-up #387, to aid reviewing and avoiding creating merge conflicts.

Assigning myself to try to do this now.

[sadielbartholomew]

Forgot to add a quick screenshot of my text editor with a whitespace-detecting mode enabled, demonstrating some of this on ch09.adoc as an example, the yellow strange symbols indicate unicode whitespace, yellow centered dots standard whitespace:

[DocOtak]

Oh... U+00A0 are non breaking space characters in ISO/IEC 8859-1. aka LATIN-1. That is not UTF-8 all (there are invalid bytes and byte sequences in UTF8).

Seeing this, we really must have some statement on the character encoding of our source documents for asciidoc and the markdown sources. This is not a statement about how to encode characters in the CF conforming data files.