Refactor beast core, http, tests, and examples:

* Fix warnings
* Port cmake scripts to linux
* Add command line options for running test suites
* Add examples to CMakeLists
* Return std::uint64_t from writer::content_length
* basic_parser::write takes asio::const_buffer instead of pointer and size
* Turn message test back on now that it passes
* Rename to http::headers, use std::allocator, remove http_headers
* http::message::method is now a string
* Refactor to_string for ConstBufferSequence
* Remove chunk_encode from the public interface
* Initialize members for default constructed iterators
* Disallow default construction for dependent buffer sequences

Refactor http::message serialization:

* Serialization no longer creates a copy of the
  headers and modifies them
* New function prepare(), sets Connection, Transfer-Encoding,
  Content-Length based on the body attributes and caller options.
  Callers can use prepare() to have the fields set automatically,
  or they can set the fields manually.
* Use write for operator<<
* Tests for serialization

test/main.cpp

@@ -17,26 +17,77 @@
 */
 //==============================================================================
 
+#include <beast/detail/unit_test/amount.hpp>
+#include <beast/detail/unit_test/global_suites.hpp>
+#include <beast/detail/unit_test/match.hpp>
 #include <beast/detail/unit_test/reporter.hpp>
 #include <beast/detail/unit_test/suite.hpp>
 #include <beast/detail/stream/debug_ostream.hpp>
+#include <boost/program_options.hpp>
+#include <iostream>
+#include <vector>
 
 #ifdef _MSC_VER
 # ifndef WIN32_LEAN_AND_MEAN // VC_EXTRALEAN
 #  define WIN32_LEAN_AND_MEAN
-#include <windows.h>
+#  include <windows.h>
 #  undef WIN32_LEAN_AND_MEAN
 # else
-#include <windows.h>
+#  include <windows.h>
 # endif
 #endif
 
 #include <cstdlib>
 
+namespace beast {
+namespace detail {
+namespace unit_test {
+
+std::string
+prefix(suite_info const& s)
+{
+    if (s.manual())
+        return "|M| ";
+    return "    ";
+}
+
+template<class Log>
+void
+print(Log& log, suite_list const& c)
+{
+    std::size_t manual = 0;
+    for(auto const& s : c)
+    {
+        log <<
+            prefix (s) <<
+            s.full_name();
+        if(s.manual())
+            ++manual;
+    }
+    log <<
+        amount(c.size(), "suite") << " total, " <<
+        amount(manual, "manual suite")
+        ;
+}
+
+template<class Log>
+void
+print(Log& log)
+{
+    log << "------------------------------------------";
+    print(log, global_suites());
+    log << "------------------------------------------";
+}
+
+} // unit_test
+} // detail
+} // beast
+
 // Simple main used to produce stand
 // alone executables that run unit tests.
-int main()
+int main(int ac, char const* av[])
 {
+    using namespace std;
     using namespace beast::detail::unit_test;
 
 #ifdef _MSC_VER
@@ -47,10 +98,41 @@ int main()
     }
 #endif
 
+    namespace po = boost::program_options;
+    po::options_description desc("Options");
+    desc.add_options()
+        ("help,h",  "Produce a help message")
+        ("print,r", "Print the list of available test suites")
+        ("suites,s", po::value<string>(), "suites to run")
+        ;
+
+    po::positional_options_description p;
+    po::variables_map vm;
+    po::store(po::parse_command_line(ac, av, desc), vm);
+    po::notify(vm);
+
+    beast::detail::debug_ostream log;
+
+    if(vm.count("help"))
     {
-        beast::detail::debug_ostream s;
-        reporter r (s);
-        bool failed (r.run_each (global_suites()));
+        log << desc;
+    }
+    else if(vm.count("print"))
+    {
+        print(log);
+    }
+    else
+    {
+        std::string suites;
+        if(vm.count("suites") > 0)
+            suites = vm["suites"].as<string>();
+        reporter r(log);
+        bool failed;
+        if(! suites.empty())
+            failed = r.run_each_if(global_suites(),
+                match_auto(suites));
+        else
+            failed = r.run_each(global_suites());
         if (failed)
             return EXIT_FAILURE;
         return EXIT_SUCCESS;