added the header file dependences to ngx_pagespeed
added the header file dependences to ngx_pagespeed

0x0mar/ngx_pagespeed,pagespeed/ngx_pagespeed,digideskio/ngx_pagespeed,wanrui/ngx_pagespeed,wanrui/ngx_pagespeed,pagespeed/ngx_pagespeed,digideskio/ngx_pagespeed,0x0mar/ngx_pagespeed