Fixed if condition error in I2B2ODMStudyHandler and some changes to OdmToFilesConverter

- Changed and (&&) into or (||) operator in first if condition of the processODMClinicalData method: if the first part is true, the second part should not be evaluated.
- Other small issues: removed empty statement (double semi-colon), changed Javadocs, made minor textual changes, suppressed an unused parameter warning, removed redundant initialization, and used for-each instead of for loop.