add multi_download.hpp to vc2005 project

Signed-off-by: Jack <jack.wgm@gmail.com>
add async example

Signed-off-by: Jack <jack.wgm@gmail.com>
fixed comment on catch

Signed-off-by: Jack <jack.wgm@gmail.com>
add sync http example

Signed-off-by: Jack <jack.wgm@gmail.com>
move example project to vcprojects dir

Signed-off-by: Jack <jack.wgm@gmail.com>