Removing various references to the threaded shells and -pylab. For now, the -pylab and -*thread command line options are no-ops, meaning that they are accepted as valid, but don't do anything. In the future we need to add messages describing how they are deprecated.

Fixing a few imports related to shell.py.

Dramatic cleanup of shell.py. Because of the new GUI event loop handling in inputhook.py, we have been able to get rid of almost all the code in shell.py. We don't need any threaded shells, so we only have IPShell and IPShellEmbed. Yah!

More testing and docstrings added for inputhook.py

Fixed import statements for inputhook.

Moving inputhook modules into IPython/lib.

First draft of full inputhook management.

Minor fixes to setupexe.py and reorg.txt.

Renaming Extensions=>extensions in code and imports.

Finishing the move of Extensions=>extensions.