doc: corrections to words and forms

This patch exchange words which are inappropriate for a situation,
deletes duplicated words, and adds particles where needed.
doc: comma placement corrections and word order

Set commas where there should be some.
Some improvements to word order.
doc: write out stdin/stdout file descriptors

"When refering to code, STDOUT/STDOUT/STDERR are replaced with
stdin/stdout/stderr, and in other places they are replaced with
normal phrases like standard output, etc."

Addendum to commit v209~127.
doc: balance C indirections in function prototypes

Shift the asterisks in the documentation's prototypes such that they
are consistent among each other. Use the right side to match what is
used in source code.

Addendum to commit v209~82.