include info log msg with name/location of used easyblock

This makes a log message like the one below to be included in the application log:

```
== 2014-10-23 19:52:16,785 main.EB_bzip2 INFO This is easyblock EB_bzip2 at <module 'easybuild.easyblocks.bzip2' from '/Users/kehoste/work/easybuild-easyblocks/easybuild/easyblocks/b/bzip2.pyc'>
```

Although the class name is mentioned twice, I feel it's important to make the log message "complete" by including it in the actual message itself.
Mostly style, yeah, put initialising variables to "empty" all together.