Introduce command-line tool for parsing build output.

It makes the functionality of Qt Creator's build-related
output parsers available on the command-line.
Concrete use case: Run this on the build machines and put
the output in the emails sent to potential build breakers.

Change-Id: Iea6870ed976790854aecfe3cdc0d5b2296b6bced
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>