fix text-decoration property in layout
change position of setting inline_data for "<span>asdf<div>b</div></span>" case
fix line-height property
add RareFlowFlags
RareFlowFlags -> ~RareFlowFlags
auto merge of #1506 : ksh8281/servo/inline_add, r=pcwalton

add inline stuff & color support
it makes same result with firefox in "http://www.w3.org/Style/CSS/Test/CSS1/current/sec543.htm"
makes line-height property can inherit