added eclipseDependency='false' behavior

While generating .classpath file maven-eclipse-plugin includes all artifacts defined in project.xml regardless of it's type. As a side effect it may be observed that even JSP's *.tld files are included as Eclipse variables.It leads to project compile problems. Actually such project won't compile at all.

To avoid such behavior I propose a silly patch attached, which takes care of eclipseDependency property of artifacts. If it is set to 'false' the artifact will not be listed in .classpath.