Revert "jaxb_library target now exists. It takes in sources=[] for the schema file(s), and a package='...' parameter for what package to generate the output java files in. It uses the xjc compiler included in the jdk (executed using nailgun, using the tools.jar library found under java_home's lib directory). Code modeled after corresponding code for protobuffers, thrift, and antlr code generation."

This reverts commit a0b1aefd811de3826423caa3ba636923e759a158.