Version 1.10 adds the ability for the build key to equip whatever is necessary to build a copy of what you're looking at. It will equip cables or pipes and the offhand tools necessary to merge them, as well as any kits or buildables you have in your inventory. Looking at completed walls will equip the matching wall kit, for example.

Version 1.9 adds crowbar-ing with the build key to force open doors, and the covers on the APC.
Configure key can equip wrench when it can do something your hands can't (turning solar panels).
Unbuild will trigger for non-structures like deconstructable crates.

General bug fixes, some features should have slightly more precise detection.

Version 1.8 fixes a whole host of bugs and weird behaviors.

Screwdriver was equipping when it could be placed into a slot.

Mountable containers like crates & portable tanks were recognizing the player as a valid mounting point, causing erroneous build/unbuild triggers and wrenches to be dumped into the world.

Protections placed against recognizing dragged crates as valid places to put items.

Don't try to equip stuff into slots containing dragged items.

Version 1.7 fixes an issue where hand swaps were not being performed in the case that one hand was empty

Thanks to Identifier

Version 1.6 prevents actions from triggering when the code editor is open

Thanks to T_BENZIN for noticing.

Version 1.5 fixes the configure key not working from a cold boot of the game, it was only working if reloaded mid-game. "Works on my machine!"

Version 1.4 adds the missing functionality of the configure key. You can now work those pesky setscrews on circuits easily! Anything that can be set directly via labeller will use it instead of a screwdriver.

Version 1.3 fixes a logic error causing full stacks to not be considered valid sources when joining an existing stack.
Also replaced another use of Stackable.Merge.

Work on the configure key continues, I am trying to get it to be precisely correct about when you can/can't use the tools.

Item moving logic is a complete mess and doesn't fulfill requests correctly in some less common circumstances. It needs a full rewrite.

Version 1.1 fixes a multiplayer issue with item stacking
[Stackable.Merge(IMergeable) does not delete empty stacks on clients, use OnServer.Merge instead]