Fix of the option --input-dir of the command sql:insert

Fix a bug in AbstractCommand.
The input-dir option was not considered for the command SqlInsertCommand.
I added a test in order to reproduce the bug.

I had to commit the file propel.yaml (in addition to propel.yaml.dist) because it's not generated on my machine and I don't know how to automaticaly generate it when we run the unittests.