Add Post Thumbnail Support

Signed-off-by: Vitor Faiante <vfwebsolutions@gmail.com>
Display Post Thumbnail on the Posts in the front page

Signed-off-by: Vitor Faiante <vfwebsolutions@gmail.com>
Add Single Post Template and Single Portfolio Template

Signed-off-by: Vitor Faiante <vfwebsolutions@gmail.com>