[python-bindings] Removed unused import byref from llvm/disassembler.py.
[python-bindings] Implemented the PassRegistry class and the calls to initialize/shutdown llvm. Also included an initialize_llvm declaration.
[python-bindings] Added bindings for LLVMContextRef and a test for creating a new context or getting the global context.
[python-bindings] Added code for loading a module from bitcode, getset its datalayout, getset its target, dump it, print it to a file.