Unify line of sight and projection paths

Some comments on this from around the place:

'Fix targetting so that "hockey stick" cannot be used anymore.'

'Perfecting LOS/FOV code should not result in the only tactical positioning choice allowing one to gain an advantage being corridor instead of room (or vice versa) or using pillar dancing (if fast).

Replace the old quirks with some interesting new quirks, even if this means adding some new feature(s).'

4gai has a good solution to this.

4GAI, yes. But still "what you see is what you target" and "if you see them, they see you" are so nicely KISS. They help newbies and they free your mind to seek tactics elsewhere, where it's not a bunch of local fixed tricks anymore, but either dynamic non-local tactical ideas (4GAI emergent behaviour and distinct monster abilities prevents repetition), or using explicit LOS or targeting advantages, like splash damage and hack and back, where 4GAI ensures fair game and so prevents boredom.