#31 [findbugs] Added target to support findbugs history

[Andrew Harmel-Law]

I've added some functionality to the 1.3.1 findbugs plugin so that not only can it generate point in time bug reports, it can also generate and collect bug history information. I've attached my new version of the plugin for you to take a look at and see if you wish to commit it.

Notes:
o I've had to update the <dependencies> in project.xml because of the version of findbugs on which the plugin now depends (1.2.1). Some of the jars which come with findbugs do not have version info in their name or in their manifest. I've improvised and added them to the findbugs dependencies directory. Another downside is that now the plugin requires findbugs to be installed seperately in order to run. This seems to be due to the fact that it needs to know where it's home is when executing.
o I had to edit the <build> section in project.xml a little to get it to build on my box. You may wish to change this back to how it was
o The element of the old tagret which uses JSTL to transform the report into XML for the Maven site now fails. I could not figure out why this was. Perhaps it is my environment.
o I have added a couple of default properties to plugin.propertiesto support all this.
o Reports are now generated and placed in a directory called "findbugs". This is configurable. Old raw files are also cleaned up each run. History files remain.

[Andrew Harmel-Law]

updated version of the findbugs 1.3.1 maven 1. plugin