[rules-dev] The working directory for unit tests should be module directory

[Geoffrey De Smet]

HI guys,

Most unit tests are working directory independent (which is a good thing),
but some unit tests are forced to use the working directory to find the 
module or project directory,
so they can:
- Write a file to "MODULE_DIR/target", such as a temp file. Hint: use 
File.createTempFile() instead if possible.
- Write a file to "MODULE_DIR/local", such as a benchmark log. That 
local directory isn't cleaned with "mvn clean" and isn't in git either.
- Retrieve a non-classpath file. Hint: Put the file in 
src/test/resources and use getClass().getResource(...) instead if possible.

By default, Maven, Gradle, Jenkins, ... sets the working directory to 
the module directory.
By default, Eclipse sets it to the project directory.

For example:
   droolsjbpm/
   droolsjbpm/drools  = project dir (unless it's droolsjbpm in some setups)
   droolsjbpm/drools/drools-compiler  = module dir

So I suggest we do the following:
- Avoid having to use the working dir in our tests
- Presume that the working dir is always the module dir - if we have no 
other choice but to use it.

-- 
With kind regards,
Geoffrey De Smet