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.

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

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.

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.

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

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

inet:gethostbyname/1 might fail for IPv6 literals, therefore check first
if host is an IPv6 address literal.

As specified in the following RFC:  http://www.ietf.org/rfc/rfc2732.txt

* Add rebar
* Move build flags from src/Makefile to rebar.config
* Remove src/Makefile
* Put version in src/ibrowse.app.src
* Remove vsn.mk
* Remove ebin/ibrowse.app
* Change Makefile to read version from src/ibrowse.app.src
* Change Makefile all target to call ./rebar compile
* Change Makefile clean target to call ./rebar clean
* Update .gitignore to ignore ebin/*

Like in synchronous programming, in makes sense to start an inactivity timer only when the caller
does a "recv" call and cancel the timer as soon as data is received from the socket.