Enemy archers, magic weapons and armour, keyboard shortcuts and more

* Amended targetting with +/- to give a choice between targeting hostile or friendly creatures first. Makes ranged combat and casting a lot faster.

* Fixed bug with casting bless and failing to select a proper target caused a crash.

* Fixed allocation of cleric spells. 2nd level spells are now all awarded at character level 3 when you get your first 2nd level spell slot. Will be maintained as higher level spells are implemented.

* Fixed allocation of wizard spells. On each level up, you can only select a new spell which is castable for your level. This stops the player picking uncastable level 2 spells from the start etc.

* Added quick fire command as 'F'. Player will attempt to make a ranged attack against the last target if that target is still active and not incapacitated.

* Added quick cast command as 'M'. Player will attempt to cast the last spell against the last target is that target is still active and not incapacitated.

* Amended all possible spells with a simple target to be passed so they work with quick casting. If a spell doesn't take a target in that way and a quick cast is attempted to use it, then it will hopefully just work like an ordinary spell.

* Fixed out of bounds bug in companion AI.

* Added basic functions for adding permanent conditions to items to enchant them. Implemented routines for adding these conditions to weapons and armour. Added name overrides to make sure that the base item name isn't changed but the enchantment is displayed on screen. Added name prefixes and suffixes as well.

* Implemented random chance of every armour and weapon found in the dungeon to be enchanted.

* Implemented distribution of higher enchanted items - 10% of any enchantment at all. From there: 5% chance of +3, 20% chance of +2, 75% chance of +1.

* Implemented monsters with range attacks. New AI type which will fight melee at close range or at distance will not approach but rather 50% of the time will make a ranged attack. Added new base stats for monsters which will be able to make ranged attacks. Started with kobold archers and they are implemented with a 10% chance of each kobold in a mob being an archer. Added flag to pass to attack routine to make sure it knows to look for ranged attack stats as opposed to normal stats in the stat block. 

* Redid movement functions to hopefully iron out some kinks by resorting to excessive long if statements. 

* Changed kobold archer to kobold slinger. Added orc chucker and bandit archer to the respective mobs.

* Fixed bug where incapacitated enemy in line of sight was preventing ally from reviving.

* Added open door on an attempt to move into a closed door rather than having to use the 'o'pen command.