Corrections to the LwDITA DTDs

I corrected the content models for the entities that were used to define content models for the highlight and emphasis domains.
Now, these domain elements do not incorrectly permit <image>.
I also simplified the entities for the inline elements.
They now are defined as follows: < !
ENTITY % inline "#PCDATA %ph; image xref %data;" > < !
ENTITY % inline.noimage "#PCDATA %ph; xref %data;" > < !
ENTITY % inline.noxref "#PCDATA %ph; image %data;"
> Best, Kris Kristen James Eberlein Chair, OASIS DITA Technical Committee Owner, Eberlein Consulting LLC 
Skype: kriseberlein; voice: +1 (919) 622-1501