Enhance Eclipse usage instructions

Updates to instructions for setting up DbFit in Eclipse.
> For IDEA the instructions imply the command is to be run from the dbfit-java dir so either .. is needed or I can remove the reference to the dbfit-java directory.

It's more straightforward if commands are executed from dbfit top dir - so let's make it that way.


> Shall I delete these 2 .project files as part of this PR?

I think it's OK to do that in this one.