[Building Sakai] lesson builder change: support for contrib tools need to be enabled

[Hedrick Charles]

To comply with Sakai rules on core tools, lesson builder 1.4 (trunk) has been changed so that dependencies on contrib tools are now in opt-src rather than src.

To enable access to YAFT or mneme you need to edit tool/pom.xml and uncomment the labelled sections. That is the only file that needs to be changed (other than getting the version numbers right for the tools that you have).

Note that Lesson Builder will build and run just fine on systems without these tools, and in fact that's the recommended configuration. It will dynamically detect what tools and present and disable the ones that aren't. 

The easy option is all contrib dependencies on or all off. While it is possible to choose just one of the contrib tools, by editing some XML files, I see no reason to do that. I don't anticipate testing versions with only some tools enabled.