allow "paths" on tags, namespace records under r.recordname

example:

    A = #r.foo {a: 1, b: 2}
    B = #r.foo A#{a:2, c:[]}
    #r.foo {a : A} = B
add binary strings with single quotes:

A = 'I\'m a binary string'
B = "I'm a regular string"
add builtin support for tagged strings to atom: C = #atom "I'm an atom"
change switch keyword to match
add builting support for char tag Char = #c "!"