Version 0.1.9 with GWT enhancements

This is a bugfix release that replaces 0.1.8, which had serious problems on GWT. There aren't many new features in this release if you don't care about targeting GWT, other than some small fixes/improvements to whitespace handling and the added G category that includes all whitespace (like the fusion of Zh and Zv, which are also available as Gh and Gv now). If you do use GWT, this release provides a super-source replacement of most of java.util.regex with fairly close behavior, at least closer than the default regex behavior in GWT where available. This needs to be tested more carefully, particularly when other libraries also super-source replacements to the same package, but the best way to do that for now is with a new release. This does remove what was the regexodus.regex package from compilation on non-GWT targets, but it replaces java.util.regex on GWT. It may be reintroduced in its own package for other platforms, though there are generally more features available if you directly use the regexodus package instead of a transitional layer. If you encounter issues with 0.1.9, you can downgrade to 0.1.7 without breaking anything, probably (0.1.7 is only on Maven Central, not released on GitHub).