Update #2 - big firefight in a small maze

So, major thing in this update is that you can now shoot stuff! But beware, the stuff shoots back.

As test enemy, I've implemented simple stationary shooting enemy type (A.K.A. turret). In a process, I've made some basis for AI, established enemy reaction on player entering and leaving room, added enemy placement to level generation via enemy patterns.

Also, some UI was added - health (as player now can take damage, it was important to see your own health for testing), energy (currently useless), and minimap. Minimap allows you to observe level layout, track your current position and already visited rooms. It still might use some tweaking, like, not showing all map initially, and showing important rooms contents (but this requires to have important rooms in the first place). Most likely, general UI layout will remain like this, the biggest possible addition being consumables (if I will ever add those).

As a following development plan, I'm thinking about adding actual energy management (would make sense to do so in game, supposed to be focused around energy management), and actual ways to spend energy aside of shooting. Also I probably should start thinking about meta-game, as currently even main character death is not handled.