[PATCH] Changes to HOWTO index page

[STemplar]

I suggest making the following changes to the HOWTO index to make it more 
intuitive and easy to grasp. Please see notes below and attached HTML file that 
shows what the result may look like.
- - - - - - - - - - - -
* Put 'Introduction to Asynchronous programming' under 'Introduction' and add 
'with Twisted' to the name (as the headline in the document already says)
* Rename 'Overview' to 'Graphical overview'
* Place 'Deferreds are beatiful!' in 'Low-Level Networking and Event Loop' and 
rename to 'Deferreds in depth'
* Move 'Twisted Spread' from 'Introduction' to 'Perspective Broker'
* Move 'Twisted RDBMS support' and 'The row database abstraction' into a new 
section 'Twisted RDBMS support'
* Under 'High-level Twisted', rename 'Using the utilities' to 'Helper programs 
and scripts (twistd, mktap, ..)'
* Remove 'Writing mktap plugins' and 'Upgrading and Rebuilding Applications' 
links from index page and put them in either 'Helper programs and scripts' or in 
'Using Application'. 
* Move 'Writing a TCP server' and 'Writing a TCP client' to 'Tutorials' 
* Give the 'Generating deferreds' howto a link in the howto index page
* In the Generating deferreds howto..  make a section that discusses different 
solutions moving from or dealing with blocking code.. i.e. deferToThread and 
such things. Link to adbapi doc
- - - - - - - - - - - - - -

[hypatia]

Making Brend nosy, since he's been doing some work on this.

[hypatia]

Your changes have been applied to the development version of the index. Thanks a
lot -- they are good suggestions!

Note for the future: index.html is actually a generated file. You want to
retrieve the source file, which is named index.xhtml from the repository and
edit that if you have future suggestions. I'm happy to help with this if you like.