fix various bugs in canonicalization

fix typo in canonicalization docs

fix bug where PointerBuilder::getPointerType() can corrupt PointerBuilder::segment

update mention of non-existent 'stepBits' field

Make sure to clear tag word when upgrading a struct list.

Edit error message for the case where copyPointer() hits a FAR pointer.

The existing error message suggests this case can only arise if there is a
a bug in the library. However, malformed input can trigger the error too.
In particular, the error gets thrown when a non-double far pointer resolves
to another far pointer.

fix bug in parsing of non-ascii constants

Fix MSVC build errors

Closes #408. Perhaps the same bug as in commit cff9ba05?

Add HTTP client and server implementation.

The old semantics were intended to allow more implementation freedom, but I find in my actual code it's very convenient to rely on the actual implementation details. Other implementations will just have to deal with it.

Let MSVC build without lite mode

Bootstrap regeneration commit to follow.