Retry requests when the worker has the connection close

When a tcp_closed or ssl_closed message is handled while ibrowse is
trying to send a request to a worker, ibrowse would incorrectly return a
req_timedout message, when, in fact, the request had not even been
handled.

This patch attempts to avoid that race condition by signalling tcp or
ssl closed messages back to ibrowse differently than a normal exit.

Allow comma-separated list in Transfer-Encoding response header.

This should, for example, allow user to specify "TE: gzip" header in request and unzip response body manually.

Added Socks5

Fixed up documentation

There's no need for this not to be here since it's a very common
operation when retrieving new dependencies. In fact, it's the first
thing I did.

I fixed the documentation errors in order to get them to build I made
a cursory check through the source to ensure that they were correct
and it seems like they are so I submit this patch.

send message after async response timeout

Comment example proxy setting from default ibrowse.conf

allow binary header values

Update counter crashed when select process shutdown.

ets update counter throws exception when the corresponding process has already shutdown. Added line fee to L248

ets:update_counter crashes when select process has shutdown.

xref and test changes

Move src/ibrowse_test.erl file to the test directory.

Add worker_process_options for start and start_link purposes

Typically used to specify non-default, garbage collection options.

Changes to app file and remove compile warnings

add missing methods

moved hrl to include dir

Returning empty bodies from the body generating function results in the end of the resource.