Translate the documentation in French

[Hywan]

@osaris will do this, reviewed by @vonglasow.

[osaris]

Here is the todo list :

• Introduction
  • Nature of tests
  • Test framework
  • Research papers
• Writing tests
  • Automated unit tests
  • Automatic test data generation
  • Automatically generated tests
• Run tests
  • Interpreting the test result
  • Debugging mode
  • Select tests to run
  • Choose the PHP virtual machine
  • Test execution engine
• Virtual file system
  • Files or directories
  • Permissions
  • Access-, change- and modify-time
• Conclusion

[vonglasow]

@osaris can you please update the progression ?

[osaris]

@vonglasow I updated the TODO :-) Please note that there is ~500 lines translated on ~750. The TODO doesn't reflect this (and there is many code samples in the remaining 250 lines, which don't need translation).