Commented Issue: test_runner httplistener_test.so crashes [45]

My application was crashing at exit with similar to the provided below callstack, and I when tried running the tests, they all passed but some of them crashed at the end.

OS: CentOS 6.4 x86_64
Compiler: GCC 4.8.1

```
... $ gdb test_runner
...
(gdb) r httplistener_test.so
...
Program received signal SIGSEGV, Segmentation fault.
0x00007ffeb80012f0 in ?? ()
...
(gdb) bt
#0 0x00007ffeb80012f0 in ?? ()
#1 0x0000000000406ea9 in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release() ()
#2 0x00007ffff77ab0c3 in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::~__shared_count() () at /devpkgs/include/c++/4.8.1/bits/shared_ptr_base.h:553
#3 0x00007ffff030e7c2 in std::__shared_ptr<pplx::scheduler_interface, (__gnu_cxx::_Lock_policy)2>::~__shared_ptr() () at /devpkgs/include/c++/4.8.1/bits/shared_ptr_base.h:810
#4 0x00007ffff030e7dc in std::shared_ptr<pplx::scheduler_interface>::~shared_ptr() () at /devpkgs/include/c++/4.8.1/bits/shared_ptr.h:93
#5 0x00007ffff03109ec in pplx::scheduler_ptr::~scheduler_ptr() () at /home/hrayr/build/casablanca/Release/include/pplx/pplxinterface.h:74
#6 0x00007ffff03114c0 in pplx::details::_TaskCollectionImpl::~_TaskCollectionImpl() () at /home/hrayr/build/casablanca/Release/include/pplx/pplx.h:138
#7 0x00007ffff0311710 in pplx::details::_Task_impl_base::~_Task_impl_base() () at /home/hrayr/build/casablanca/Release/include/pplx/pplxtasks.h:1739
#8 0x00007ffff033220e in pplx::details::_Task_impl<unsigned char>::~_Task_impl() () at /home/hrayr/build/casablanca/Release/include/pplx/pplxtasks.h:2437
#9 0x00007ffff033af55 in void __gnu_cxx::new_allocator<pplx::details::_Task_impl<unsigned char> >::destroy<pplx::details::_Task_impl<unsigned char> >(pplx::details::_Task_impl<unsigned char>*) () at /devpkgs/include/c++/4.8.1/ext/new_allocator.h:124
#10 0x00007ffff033725f in std::enable_if<std::allocator_traits<std::allocator<pplx::details::_Task_impl<unsigned char> > >::__destroy_helper<pplx::details::_Task_impl<unsigned char> >::value, void>::type std::allocator_traits<std::allocator<pplx::details::_Task_impl<unsigned char> > >::_S_destroy<pplx::details::_Task_impl<unsigned char> >(std::allocator<pplx::details::_Task_impl<unsigned char> >&, pplx::details::_Task_impl<unsigned char>*) () at /devpkgs/include/c++/4.8.1/bits/alloc_traits.h:281
#11 0x00007ffff0332768 in void std::allocator_traits<std::allocator<pplx::details::_Task_impl<unsigned char> > >::destroy<pplx::details::_Task_impl<unsigned char> >(std::allocator<pplx::details::_Task_impl<unsigned char> >&, pplx::details::_Task_impl<unsigned char>*) () at /devpkgs/include/c++/4.8.1/bits/alloc_traits.h:405
#12 0x00007ffff032a951 in std::_Sp_counted_ptr_inplace<pplx::details::_Task_impl<unsigned char>, std::allocator<pplx::details::_Task_impl<unsigned char> >, (__gnu_cxx::_Lock_policy)2>::_M_dispose() () at /devpkgs/include/c++/4.8.1/bits/shared_ptr_base.h:407
#13 0x0000000000406ea9 in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release() ()
#14 0x00007ffff77ab0c3 in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::~__shared_count() () at /devpkgs/include/c++/4.8.1/bits/shared_ptr_base.h:553
#15 0x00007ffff03127ca in std::__shared_ptr<pplx::details::_Task_impl<unsigned char>, (__gnu_cxx::_Lock_policy)2>::~__shared_ptr() () at /devpkgs/include/c++/4.8.1/bits/shared_ptr_base.h:810
#16 0x00007ffff0312802 in std::shared_ptr<pplx::details::_Task_impl<unsigned char> >::~shared_ptr() () at /devpkgs/include/c++/4.8.1/bits/shared_ptr.h:93
#17 0x00007ffff031281c in pplx::task<unsigned char>::~task() () at /home/hrayr/build/casablanca/Release/include/pplx/pplxtasks.h:3186
#18 0x00007ffff0312bb6 in pplx::task<void>::~task() () at /home/hrayr/build/casablanca/Release/include/pplx/pplxtasks.h:4159
#19 0x00007fffef7e2d89 in web::http::experimental::listener::http_linux_server::~http_linux_server() () at ../include/cpprest/http_linux_server.h:193
#20 0x00007fffef7e2df4 in web::http::experimental::listener::http_linux_server::~http_linux_server() () at ../include/cpprest/http_linux_server.h:194
#21 0x00007fffef810174 in std::default_delete<web::http::experimental::details::http_server>::operator()(web::http::experimental::details::http_server*) const () at /devpkgs/include/c++/4.8.1/bits/unique_ptr.h:67
#22 0x00007fffef80fa13 in std::unique_ptr<web::http::experimental::details::http_server, std::default_delete<web::http::experimental::details::http_server> >::~unique_ptr() () at /devpkgs/include/c++/4.8.1/bits/unique_ptr.h:184
#23 0x00007ffff6a78da2 in exit () from /lib64/libc.so.6
#24 0x00007ffff6a61ce4 in __libc_start_main () from /lib64/libc.so.6
#25 0x0000000000404c81 in _start ()
(gdb)
```
Comments: We believe this issues has been fixed. All of the listener tests should be passing now, with the exception of known issues with open bugs and the test case disabled. Let us know if you still see any issues.