CodingStyle: add information about trailing whitespace

and no space around the '.' and "->" structure member operators.

Do not leave trailing whitespace at the ends of lines.  Some editors with

"smart" indentation will insert whitespace at the beginning of new lines as

appropriate, so you can start typing the next line of code right away.

However, some such editors do not remove the whitespace if you end up not

putting a line of code there, such as if you leave a blank line.  As a result,

you end up with lines containing trailing whitespace.

Git will warn you about patches that introduce trailing whitespace, and can

optionally strip the trailing whitespace for you; however, if applying a series

of patches, this may make later patches in the series fail by changing their

context lines.

		Chapter 4: Naming