[fix test api] Only change Origin headers in WebSocket requests when the `changeOrigin` option is set explicitly. Added tests to ensure Origin and sec-websocket-origin headers match when proxying websockets.

[test] Improve websocket tests to inspect outgoing and incoming HTTP headers to test origin mismatch bugs

Tests can be run in https mode by adding the --https flag
vows test/*-test.js --spec --https

Readme: fix syntax error, reformat code blocks

[fix] Manage bookkeeping for incoming requests to the underlying sockets behind reverse proxied websocket events. Only use the appropriate variables in the closure scope of the `upgrade` event from this bookkeeping

This reverts commit 642e1580.

Looks like this may fix the issue that I reported

[doc api] Update README.md and CHANGELOG.md for v0.5.0. Update bin/node-http-proxy to read files specified in `config.https`

[api] Update `.proxyRequest()` and `.proxyWebSocketRequest()` APIs to take an options hash instead of a set of arguments. Add HTTPS support.

[api] Update `request` event to be consistent by emitting both `req` and `res`. Add `x-forwarded-for` header.