Removed characters stack from handler

[andrew-aladev]

Closes #1561.

libxml2 reports all characters between any two tokens, so it looks like we don't need a characterStack in handler.

[kares]

Hey Andrew! which JRuby are you guys using? (personally was hoping for a JRuby 1.7.x compat release)

[andrew-aladev]

@kares, Hello. I am using jruby-9.1.6.0 but this pull request works fine with jruby-1.7.26.

[kares]

@andrew-aladev yy ... its that the official release 1.7 (this eventually gets into) dropped JRuby 1.7 support

[kares]

disregard my comments, MRI < 2.1 support was dropped but JRuby 1.7 support is kept, for now. 🆒

[flavorjones]

Hi! Thanks for submitting this PR.

There's a lot going on in this pull request that's not completely explained by either the PR description or the commit log.

For example, in the first commit you introduce a new file, and a later commit renames that file, and then an even later commit adds that file to the gem manifest. These should all be done in a single commit along with the new feature being tested.

Other commits make changes to the test helper's Document object that are not related to the code being changed.

I'm not necessarily opposed to any of these changes, but I'd like to ask you to clean this up so that each commit makes (and explains) one change, and the series of patches tells a story.

[andrew-aladev]

Ok. I will provide a separate commit for each change.