The patch set has been revised according to reviews 1. options documented in commit messages 2. typos fixed 3. confugure/Makefile melded into one commit
Following changes were introduced since the last review: 1. Makefile launches wilx in quite mode. 2. configure script explicity valudates option setting and complains on mismatch if MSI package build is enabled without guest agent or MinGW cross-compilation: in the previous version, absence of guest agent and MinGW made the script to silently drop MSI package build.
