It turns out that even with -Wall you don't get -Wshadow unless you ask for

It turns out that even with -Wall you don't get -Wshadow unless you ask for
it explicitly. I turned it on (after encountering a variable shadowing bug,
of course) and fixed all of the shadowing issues.

git-svn-id: https://svn.code.sf.net/p/freetel/code@1470 01035d8c-6547-0410-b346-abe4f91aad63