Patch submitted by Chris Pepper <pepper@...>, tweaked.
* doc/book/book/ch00.xml:
Consistently use "command-line" rather than "commandline".
* doc/book/book/ch01.xml:
Consistently use "command-line" rather than "commandline".
Remove spaces around '—' to conform with the style guide.
* doc/book/book/ch02.xml:
Clean up some redundant and awkward wording.
* doc/book/book/ch03.xml:
Clean up some redundant and awkward wording.
* doc/book/book/ch05.xml:
Remove spaces around '—'.
* doc/book/book/ch06.xml:
Consistently use "command-line" rather than "commandline".
* doc/book/book/ch09.xml:
Remove spaces around '—'.
