Fix unsafe buckets, fix dispenser handing and improve documentation

[totemo]

This pull fixes two issues:

• Unsafe buckets turning into safe buckets.
• Dispensers marked as unsafe dispensing safe liquids anyway.

In the past, to make a dispenser dispense unsafe liquid, you had to mark both the dispenser and the location of the dispensed liquid as unsafe. The new code just requires that the dispenser is unsafe; it then "does the right thing".

The documentation clarifies the use of the inspector tool item and tool block. The tool block is fairly confusing: it will always operate on the block adjacent to whatever side of the block you click on. This is confusing because when you left click with the inspector tool block, the clicked block briefly disappears (a cancelled block break), making you think you are querying that block.

I would argue that the tool item is now sufficiently easy to use that it can be enabled for use by moderators by giving the ModMode group the safebuckets.tools.item permission. Moderators can then handle ModReqs concerning dispenser flow.

I would also argue that the inspector tool block (lapis ore) is redundant (except for checking the safety of already placed liquids), confusing (despite my best attempts to explain it) and takes away admins' ability to build with lapis ore, and that therefore they would be better off not having the safebuckets.tools.block permission.

[totemo]

redwall pls

[totemo]

GitHub is a magical thing.