Fix config files lookup

I purpose a new location way.

It try to find "bin" and "lib" in the dir or go to subdir. Try 10 times max. If nothing is found, keep the script dir.

I have add '.dancer_app' file, that method can simplify a lot the dancer app root directory look up.

This solve all issues I have with Dancer::Test and use "App".
=> the current lookup of config was in "lib" during the test, which fail all my test.