libtomcat7-java (tomcat7-common) package doesn't include tomcat-dbcp.jar (which is required and different from apache-commons-dbcp)

Description of problem:

Version-Release number of selected component (if applicable):
- libtomcat7-java (7.0.52-1ubuntu0.1) / tomcat7
  (http://packages.ubuntu.com/trusty/libtomcat7-java)

How reproducible:
- If you install it, you won't see ${catalina.home}/lib/tomcat-dbcp.jar.

Steps to Reproduce:
1. Install tomcat with it.
2. Check if tomcat-dbcp.jar exists under ${catalina.home}/lib/.

Actual results:
- Because tomcat-dbcp.jar is missing, if you define a JNDI DataSource in context.xml file (in either $CATALINA_BASE/conf/ or war) [1], tomcat fails to initialize DataSource, leaving the following logs:

WARNING: Failed to register in JMX: javax.naming.NamingException: Could not create resource factory instance [Root exception is java.lang.ClassNotFoundException: org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory]

Please note that tomcat-dbcp.jar from the ASF official release contains the org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory class, not in commons-dbcp.jar.

[1] https://tomcat.apache.org/tomcat-7.0-doc/jndi-resources-howto.html

Expected results:
- It shouldn't meet ClassNotFoundException: org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory while initializing DataSource resource.

Additional info:
- http://stackoverflow.com/questions/14712308/ubuntu-tomcat7-java-lang-classnotfoundexception-org-apache-tomcat-dbcp-dbcp-bas/25941303
  (this problem was shared in StackOverFlow already long time ago.)