Presenter: Initial commit.

Panorama Presenter could be used for presenting images and videos.
There is possible present panorama reasonable way without delays.

Control keys:
   esc                   exit program
   space, right, down    next_image
   left, up              prev_image
   a                     present panorama like moveable rectagnle
   d                     present panorama like cylinder
   s                     present panorama like cylinder with stop on end of panorama
   w                     return to init image position and view
   r                     change to rectangle form
   c                     change to cylindrical form
   t                     transform to cylindrical form
   u                     transform to rectangle form

Image name format for panorma.
  name#angle.jpg
    angle in degree
    if angle is sub zero no slide animation is used when image is switched.
 examples:
  name#360.jpg      Show image in full cylinder and slide when image is switched.
  name#-60.jpg      Show image on 60° without slide.

When the cursor is in bottom side of window then miniature of images are displayed
and could be used for faster moving through images.

Signed-off-by: Jiří Župka <jzupka@gmail.com>
Presenter: Makes animations more fluent.
Add support for clang

Signed-off-by: Jiří Župka <jzupka@gmail.com>
limit count of threads for loading images.

Leave some free cpu for opengl thread

Signed-off-by: Jiří Župka <jzupka@gmail.com>
Makes animation more smooth.

Signed-off-by: Jiří Župka <jzupka@gmail.com>
Increases cache size and adds supported video format.

Signed-off-by: Jiří Župka <jzupka@gmail.com>