instead of using the old baseName=smack appendix=project.name approach,
we are now going convention over configuration and renaming the
subprojects directories to the proper name.
Having a prefix is actually very helpful, because the resulting
libraries will be named like the subproject. And a core-4.0.0-rc1.jar is
not as explicit about what it actually *is* as a
smack-core-4.0.0-rc1.jar.
SMACK-265
Also change StringUtils.escapeForXML() and Packet.toXML() to return
CharSequence instead of String. XmlStringBuilder now has 'optX' methods.
Remove XmlUtils in favor of XmlStringBuilder
Change all \r\n into unix style newlines. Add missing newlines at the
end of a file and activate the newline checkstyle module, that enforces
'\n' as newline and a newline at the end of every file.