Follow up to fix for https://issues.apache.org/bugzilla/show_bug.cgi?id=56400
- Update description of DBCP packaging in buidling.txt
- remove DBCP2 and Pool2 versions from build.properties.default
- update svn-merge docs
- remove external tomcat-dbcp.jar from sample Eclipse class path
- remove reference in Javadoc to class that does not exist

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1594015 13f79535-47bb-0310-9956-ffa450edef68