and "nothing".
Until now only products of type names were allowed: I extended
them to allow type expressions.
Removed the destructive update of a map binding "a[b] := c".
Record projection has been extended to allow for qualified
names: "a.b.c" and "a.b.c[d]".
Changed the LIGO extension from ".li" to ".ligo".
Fixed the name of the language to be "LIGO" (instead of "Ligo").
