alias: resolve recursively.

* src/dctc/java/com/dataiku/dctc/configuration/Alias.java: Here.
s3: If no son is found, the path is a file.

Closes #49.

* src/dctc/java/com/dataiku/dctc/file/S3File.java: Here.
time dimension: Compute the right pattern. Clean getValueFromId.

* src/core/java/com/dataiku/dip/partitioning/TimeDimension.java: Here.