Fix sequencer crash when pasteing strips after creating new file

Issue happened for scene. movie clip and mask strips, which contains
pointers to datablocks which are freeing on loading new file.

Also, scene strip would crash when pasted from clipboard after scene
was unlinked from file.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54935 954f8c5b-7b00-dc11-b283-0030488c597c
Draw a checker board as a background for animation player

This makes it easier and useful to investigate alpha channels,
without this straight colors are displayed on the screen which
are completely useless in case of player.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54936 954f8c5b-7b00-dc11-b283-0030488c597c
Changed a way how RGB images are saving from RGBA

Before alpha channel was simply ignored causing bad looking
straight colors which is pretty much useless.

Now saving RGB would alpha-over image on top of black color,
which makes final image look really nice. It's also very
such the same what other graphics software does this.

In the future we could easily support configurable backdrop
color, which would be really the same as other SW does it.

Also, it'll probably worth adding the same mode to RGB
display of image editor.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54937 954f8c5b-7b00-dc11-b283-0030488c597c
This lines are also not so much useful for now.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54938 954f8c5b-7b00-dc11-b283-0030488c597c
Header cleanup in libmv c-api

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54939 954f8c5b-7b00-dc11-b283-0030488c597c