[WIP] Fixed the possibility to have a smiley glue to open and close tag

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Related tickets | #44, #75, #79
| License       | MIT

* TODO:
  - [ ] Added tests with a large set of posts with complex BB code https://github.com/milesj/decoda/issues/75#issuecomment-49655654 
  - [ ] Write good commit messages, for this changes it's important.
  - [x] Removed the back compatibility break