linux-capture: Add X border option to xcomposite

XComposite, which is currently our only capture method for windows,
doesn't handle X border width. This works in a lot of cases but anytime
there's a border, a bug occurs where the lower right is clipped.  This
patch has two goals:

1) To position and size the capture texture correctly in accordance to
the border.

2) Adds a configuration option to allow people to toggle it (which in
most cases will simply do nothing) with a default of not including it.
Fixed 2 minor spelling errors.
Merge pull request #298 from ThoNohT/patch-1

Fixed 2 minor spelling errors.
Fix creating textures from image data with flipping

When the image data is copied into a texture with flipping set to true
each row has to be copied into the (height - row - 1)th row instead of
the row with the same number. Otherwise it will just create an unflipped
copy.
Merge pull request #299 from reboot/fix_creating_flipped_textures

Fix creating textures from image data with flipping