CCTextureAtlas::updateQuad modify for the memcpy hot spot

change the place that call CCTextureAtlas::updateQuad method to
update the quads with pointer reference directly.

Signed-off-by: Yongqin Liu<liuyq0307@thundersoft.com>
CCLabelAtlas.cpp: add check for n when call setDirty

in CCLabelAtlas::updateAtlasValues, there is the case that n equal to 0,
so we need to check it before when call m_pTextureAtlas->setDirty(true) and do
other process.

Signed-off-by: Yongqin Liu <liuyq0307@thundersoft.com>
Add out of bound check for the index before do the update

Signed-off-by: Yongqin Liu  <liuyq0307@thundersoft.com>
Fix the bug for the bound check

Signed-off-by: Yongqin Liu  <liuyq0307@thundersoft.com>
Revert the CCSprite.cpp and CCSprite.h to first merge other changes

Signed-off-by: Yongqin Liu  <liuyq0307@thundersoft.com>
Merge pull request #2652 from liuyq/memcpy

CCTextureAtlas::updateQuad modify for the memcpy hot spot