Refonte de la documentation sql2canopsis

Closes #1

See merge request !4

* Remove useless doc/index.rst file

* Try to make things clearer.

* This tool needs Python >= 2.7.10 with UCS4: switch to a simpler test to
  make sure everything is OK before running the tool.

* Make some commands more portable for CentOS and Debian (especially for
  MySQL / MariaDB).

Merge branch 'develop' of ssh://git.canopsis.net:2222/canopsis-connectors/connector-sql2canopsis into develop

But most important thing, fetch results by batch instead of everything at one time.

This avoids huge memory consumption on big tables.

Feature state : add state comparison capabilities



See merge request !2

Merge branch 'feature-state' of ssh://git.canopsis.net:2222/canopsis-connectors/connector-sql2canopsis into feature-state