Update the code detecting the default include and library paths

Make it be one big AWK script instead of a ton of smaller
processes. Also handle the defaults inside the AWK script for
simplicity.

Since the output is a qmake variable, we do not need to surround with
quotes strings that don't contain spaces.

Also, use a tee trick to print the verbose output: we get the actual
output from awk.

Change-Id: I4a48a917c988a6b03d2c3b6990765301287713ef
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>