White space processing

White space between inline blocks should be affected by the word-spacing property. https://bugs.webkit.org/show\_bug.cgi?id=69072

The following strings must be the same:

x x x

xxx

x x x

xxx

x x x

x xx

x xx

xx x

xx x

The following strings must be the same:

x x x

xxx

x x x

x x x

x x x

xx x

xx x

The following strings must be the same:

xxx

xxx

xxx