check if props exist before running connection.id

this patch fixes an issue with constructor-hydrate behaviors when a Map type is instantiated without a props object passed to it.

See #516

Move packages as devDependencies

move can-observable-* packages to development dependencies (devDependencies)

#512

Fix the production build for non-steal bundlers for 3.x versions

v3.2.6

3.2.6

Fix the production build for non-steal bundlers

v4.0.1

4.0.1

Removal of can-connect/tag/

This is a breaking release that moves can-connect/tag/ to its own repo, can-connect-tag.

Fix highlighting in the docs & tests in IE11

• Adding javascript parsing for #499 7ff6cf2
• Fix the tests so all of them can run in IE #501

Bump the semver range for can-type

• Bump the semver range for can-type #497
• Fix JSHint and linting errors #498

Remove can-util

• Remove can-util usage
• Fix can-connect/can/map/map with can-observable-object test

#492

Remove npm version dependency

This removes the dependency of npm version in package.json which caused error during installation.

#487

Mutiple entries support

This fixes the ability to add multiple entries:

var set = new WeakReferenceSet();

var item1 = {};
var item2 = {};
var item3 = {};

set.addReference(item1);
set.addReference(item2);
set.addReference(item3);

set.get(item1) // => item1
set.get(item2) // => item2
set.get(item3) // => item3

#486