hy-repr mishandles lexically illegal symbols and keywords

[Kodiologist]

Currently, the hy-repr of (HySymbol "a b") is 'a b, which obviously doesn't work. I initially thought we could use something like (HySymbol "a b"), but that's not correct in general; e.g., ((HySymbol "foo") x) is not equivalent to (foo x).

The most obvious solution to this is to implement a way to quote symbols (#1117) and use that. Alternatively, it may be possible to solve this with quasiquoting.

The good news is that this is an incredibly obscure bug, because what reason would one have to construct a lexically illegal symbol or keyword in the first place?