v0.0.12

Notable changes:

• C++ indexer: rename /kythe/edge/defines to /kythe/edge/defines/binding
• Java extractor: change failure to warning on detection of non-java sources
• Java indexer: defines anchors span an entire class/method/var definition (instead of
  just their identifier; see below for defines/binding anchors)
• Add public protocol buffer API/message definitions

Notable additions:

• Java indexer: ref anchors span import packages
• Java indexer: defines/binding anchors span a definition's identifier (identical
  behavior to previous defines anchors)
• http_server: add --http_allow_origin flag that adds the Access-Control-Allow-Origin header to each HTTP response