Add recipe for learn python the hard way and do some changes in ITL about the TOC

1.  增加了learn python the hard way
2.  对Introduction_to_Linux.recipe的TOC稍稍改了下，大致的样子是这样子的

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Introduction
====1. Why this guide?
====2. Who should read this book?
====3. New versions and availability
====4. Revision History
====5. Contributions
====6. Feedback
====7. Copyright information
====8. What do you need?
====9. Conventions used in this document
====10. Organization of this document
1. What is Linux?
====1.1. History
====1.2. The user interface
====1.3. Does Linux have a future?
====1.4. Properties of Linux
====1.5. Linux Flavors