xf86-video-ast: Changes to 'master'

[Y.C. Chen]

 src/ast.h        |   67 +++++++++++++++++-----------
 src/ast_driver.c |  129 +++++++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 155 insertions(+), 41 deletions(-)

New commits:
commit c1580a0f4625155514cd427a4eb9aa972b7484bb
Author: Y.C. Chen <yc_chen at aspeedtech.com>
Date:   Wed Aug 7 14:49:47 2013 +0800

    Support ShadowFB if no XAA