1. Allow single-quotes in urls, but escape them.
2. Add comments about which RFCs we're following for guidance.
3. Handle any invalid character in the hostname portion.
4. lcase protocol and hostname portions, since they are
case-insensitive.

fixes #888

When creating multiple .pipe()s to the same destination stream, the
first source to end would close the destination, breaking all remaining
pipes. This patch fixes the problem by keeping track of all open
pipes, so that we only call end on destinations that have no more
sources piping to them.

closes #929

Fix #670

Previously the return value of write was dependent on if it was paused or
not which was causing a strange error demoed in the previous commit.

Fixes #892

The secureProtocol option to building the SSL context was not being properly
passed through in the credentials in the tls code. This is fixed.

Cherry-pick fail. Breaks linux. Will land again shortly.

This reverts commit e8cf98c8.
This reverts commit d953856d.
This reverts commit 752bbd6b.

closes #916.

Problem: Sometimes it is useful to read a file from a certain position
to it's end. The current implementation was already perfectly capable
of this, but decided to throw an error when the user tried to omit
the end option. The only way to do this, was to pass {end: Infinity}.

Solution: Automatically assume {end: Infinity} when omitted, and remove
the previous exception thrown. Also updated the docs.

closes #801.

Fixes GH-913.

Fixes the circular reference problem. Closes GH-822.

Fixes GH-907.

Closes GH-867.

Thanks Frederic. Closes GH-859.

Closes GH-852.

However, this test is failing for some quite unrelated issue.
Getting some odd "socket hangup" crashes, and only the first request
ever makes it to the server.

Calling resume() immediately after calling pause() would trigger
a race condition where it would try to read() from a file
descriptor that was already being read from, causing an EBADF