Revert "Update it_IT.lang"
Update it_IT.lang

Reverted https://github.com/Azanor/thaumcraft/pull/1329 as it contained many spelling errors and wrong translations.
Reimplemented https://github.com/Azanor/thaumcraft/pull/1280 changes to align it_IT to the last Thaumcraft release (most possibly Azanor could not pull this due to having already pulled the previous, causing conflicts) and corrected some spelling

TODO Reimplement those changes from the reverted pull that truly fix grammar and spelling errors :D
Update it_IT.lang

Spelling corrections following https://github.com/Azanor/thaumcraft/pull/1329.
Also corrected a couple more issues.
Changed all the instances of "flux" from flusso back to "flux". This is to
a) make it easier for Italan asking for help to actually translate their requests
b) avoid confusion between "flusso" of air from bellow or essentia and "flux" meant as the bad effect
c) mantain constitency. Essentia is kept as such. Flux should be, too.

Also changed some words around on my own, trying to adhere to what i think it's the correct italian spelling, but i might be proven wrong (old dictionaries are old)
This should be the last thing...

Merge it and we should be ok.
Merge pull request #1 from TheVikingWarrior/patch-17

This should be the last thing...
Merge pull request #1355 from ThePB/revert-1329-patch-2

Reverting and reupdating it_IT with spelling and grammar corrections.