Remove arbitrarly chosen extra_float_digits connection option.

[orian]

No description provided.

[johto]

1. Why do we want to remove this?
2. Not arbitrarily chosen.

[orian]

It caused me some problems and I would prefer the driver to stick to the database default (or at least document it).

Imho it should be like with default libs, if a user uses simple connector, it should use the default config, but it should also be possible to pass user specific config. I can provide simple proof-of-concept.

I've forked the lib and using my fork to not mess others people assumed behavior.