Update version for DEV activity on new ttv-1.0.0 branch.
(1) ensure #PCDATA of pruned foreign elements is also pruned (fixes #20);
(2) udpate version to 1.0.Xdev for ttv-1.0 branch development;
Ensure attributes in TT Metadata, Parameter, and Style Namespaces are defined (fixes #23).
Merge fix for Issue #23.