Fix docs on http package

The recent change to throw errors wasn't done to completion.
Update the examples and some of the prose.
Fail explicitly when publishing non-cursors
Update History.md
Bump docs meteor release

Conflicts:
	docs/.meteor/release
Merge branch 'master' into devel
Increase buffer size for phantomjs in spiderable. Our docs were too big.
Clone Meteor.Errors properly. Fixes #1482.

This fixes #1482 because EJSON.stringify clones its argument; this
change ensures that when it does that, it gets a Meteor.Error rather
than just an Object with some fields from the old Meteor.Error (which,
if the Meteor.Error was passed through a Future, will not include all
the fields we expect because they are not all enumerable).
Tests for update/upsert with $push/$each.

Test adapted by mcbain's test from #1492.
remove duplicated sleep function in tests. Fixes #1496.
Calculate settings file hash properly. Fixes #1497.

Previously we were hashing the Unicode string, not the bytes.

This also removes a race condition. Now there is only one use of
watchSet.addFile which does not go through
watch.readAndWatchFile (adding package.js hashes to multiple watch sets
at once), and that use does correctly hash the bytes.