svn cp from devel/maven33

Apache Maven is a software project management and comprehension tool. Based on
the concept of a project object model (POM), Maven can manage a project's
build, reporting and documentation from a central piece of information.

WWW: http://maven.apache.org/

Add CONFLICTS_INSTALL for devel/maven3, devel/maven31, devel/maven33[1]

PR:		220959
Submitted by:	jonc@chen.org.nz
Approved by:	[1] portmgr blanket