Start using wildcards for exclusions

Maven 3 supports using * for group ID and artifact ID in exclusions. We should use them throughout the root pom.xml.

In current Maven versions there's an annoying warning printed, but it can be ignored (the warning is a bug). See http://jira.codehaus.org/browse/MNG-3832 for discussion and info (the bug says "fix version 3.2" but that's just the version in which the warning was fixed, not the actual feature).