Convert the project structure to Maven.

- Source version is actually 1.5 but considering to use version 1.6 features
  taking into account that 1.6 is the average minimum version of Java,
  that some dependencies are also at 1.6 and that it should be sufficient.

- Fix the license to be the same across all files and limited to the
  'com.sforce' package.

- Change the configuration files extensions from '.txt' to '.xml'.
Upgrade to SFDC Partner WS API v29.0.

Upgrade the dependency to Salesforce.com Partner Web Services API
Version 29.0.