SpannableBuilder will now extend SpannableStringBuilder. The major diff-
erence will be that the span order will be reverted upon a call of
`getSpans()`. Another addition will be support for setting multiple
multiple spans by array.
The reverse order implementation is credited Uncodin/bypass
* Update build configuration
* Update commonmark to 0.11.0 and android-gif to 1.2.14
* Add module `library-syntax`
* Add default prism4j theme implementation
* Add syntax highlight to sample app
* Update syntax highlight to use SpannableStringBuilder
* Working with syntax rendering
* Add darkula theme to syntax highlight
* Add attribute for image-loader module
* Update version to 1.1.0-SNAPSHOT
* Updating build configuration for snapshot publish
* Add headingTypeface, headingTextSizes to SpannableTheme (#51)
* Add headingTypeface to SpannableTheme, use a custom heading typeface in the sample app
* Add headingTextSizes
* Switching to headingTextSizeMultipliers, adding validating annotations, adding example
* Consolidate logic, add crash if header index is out of bounds
* Add small version clarifications
* Introduce MediaDecoder abstraction for image-loader module
* Switch to use SpannableFactory
* Switch to use SpannableFactory for html parsing
* Update sample application to add play-pause functionality for gifs
* Small cleanup
* Update prism4j version 1.1.0
* Update build configuration
* Add README to library-syntax module
* Update README
* Initialized custom extension module
* Upgraded android gradle plugin to 3.0.1
* Shaping up the custom extension module
* Added README to module
* Small improvement for IconVisitor (added color null check)
