Merge branch 'release/2.1.2' into develop
[BUGFIX] Constant autoload in rbx C extensions doesn't work properly
[CS] Allow CI build to fail on ruby-head

Travis is having problems with it, and it might itself be unstable
Update README.md with a section for external dependencies and include pcre
Merge pull request #13 from vindir/feature/pcre-deps

Update README.md with a section for external dependencies and include pc...
Improve formatting of deps docs and mention JRuby exclusion on PCRE
[CS] Remove niceogiri dependency by bringing in everything we need from it
[BUGFIX] Cleaner failure message if PCRE headers can't be found

Fixes #11
[CS] Avoid C compiler warning when we don't have C99
[CS] Build full SSML/GRXML documents in a single document

Both drawing and importing.
[CS] Stop subclassing/copying nodes around

Use delegators instead where they're required
[CS] No more autoload since active support changed from under us
[CS] No more official support for Ruby 1.9.2

Activesupport dropped support
[BUGFIX] Get back Java 1.6 compatibility

* By not using regex named groups in Java land
[CS] No need to test something that's not part of the API promise
[CS] Some tests should not have been pending
[BUGFIX] Nokogiri on JRuby has some trouble finding namespaces attributes
[CS] Add back concatenation support
[BUGFIX] Protect against C buffer overflow using really long digit buffers
Merge branch 'feature/no_more_mr_niceogiri' into develop