the great api -> backend rename
we regret the excesses of our previous api culling. restore some apis.
Merge branch 'master' into api-to-backend-in-one-easy-step

* master:
  Make use of currentmodule to maybe reduce redundant module definitions and also get source links.
  Enable the new read the docs theme, it's pretty.
  use is for identical object comparison
  add gcm constants and EVP_CIPHER_CTX_ctrl macro
  md5 is 128-bit. The person responsible for this mistake has been shot
  add test to verify api is being copied in hash
  When copying a hash, pass the api through to the new object
more backend renames from merged commits
Merge pull request #172 from reaperhulk/api-to-backend-in-one-easy-step

The great api -> backend rename