C++ Network Library Code

Test commit. Just a bit of cleanup.

Patch submitted by Allister Levi Sanchez to allow running tests directly from the tests directory on linux.
See: http://sourceforge.net/mailarchive/forum.php?thread_name=62aa5bc60808080920q2530dd3bi9a0ed96686c96acb%40mail.gmail.com&forum_name=cpp-netlib-devel

Allows running of the tests from both the root of the http_integration branch and the libs/network/test directory on windows.

Note: Uses ugly code repetition hack.

Ensured proper line endings for headers on both windows and linux by using sys.stdout.write

Updated tests with patch. https://sourceforge.net/mailarchive/forum.php?thread_name=eb301af30808100222oda275aaj51bd341719b8a4de%40mail.gmail.com&forum_name=cpp-netlib-devel

Fixing CGI script that doesn't respond correctly with HTTP headers.
Adding BOOST_REQUIRE_NO_THROW() to calls to client.get(...) in cgi_test.

Making some to fix compilation error issues in MSVC, addresses build issues with Asio headers and namespace clash in HTTP client implementation.

Better handling of received headers to remove leading/trailing white space.

Changes:
- making basic_request<Tag> inherit from basic_message<Tag>
- implementing stub http::errors namespace
- re-implementing HTTP client to use lower level ASIO constructs instead of high level stream interface
- refactoring traits from Tags

Fixed incorrect string comparison in test cases. The code now uses std::mismatch to find the point of difference.
Fixed "fatal error" test report on linux on sending a signal to the python server to shut down. The code no longer waits for the shut down of the server, however, a method to kill the server process safely has to be found for both linux and windows to ensure complete automation of regression tests.