changes the reflection project's id back to "core"

artifactName only affects filenames, not publishing urls, and nothing
else I've tried helps. so I'll be reverting for the time being
something a bit better: now we can write `> project reflection`
adds Lit.Bool.apply

it's super-inconvenient to have to branch yourself when you have just a value
of type Boolean and no clue what it is
adds Lit.Bool.unapply and Bool.value

matching against Lit.True and Lit.False is also quite annoying
changes private[xxx] methods

* internalWithParent is now private[core]
* tag is now $tag and is not longer private to any package
expands host docs with a recommendation for a package name
Lit.True/Lit.False => List.Bool
scala.reflect.hosts => scala.reflect.internal.hosts
oops
Merge pull request #44 from xeno-by/master

miscellaneous minor updates