Prepare for 2.12.0 release

[elihart]

• Breaking Several updates to the Paging Library integration were made (Update paged list #421)

  • The PagingEpoxyController class had the methods setNumPagesToLoad and setPageSizeHint removed
  • Page hints are now taken from the Config object off of the PagedList. See the setConfig javadoc for information on how config values are used: https://github.com/airbnb/epoxy/blob/master/epoxy-paging/src/main/java/com/airbnb/epoxy/paging/PagingEpoxyController.java#L220
  • Several tweaks were made to how the page size and prefetch distance affect model rebuilding. Take some time to make sure your config values make sense and produce good results for your use case
  • A crash on empty list was fixed (Paging: IndexOutOfBounds #420)

• New The Paris library is now officially supported to allow dynamically styling RecyclerView items though Epoxy models. See the wiki for more info.