GNUnet 0.7.1 released

This new version represents over 16 months of development and testing.
GNUnet 0.7.1 is largely compatible with GNUnet 0.7.0. Except for changes to 
the configuration file updating should be relatively unproblematic, read the 
UPDATING file for details.

The main *new* dependencies are:

* GNU's libextractor >= 0.5.14
* Guile >= 1.8
* libcurl >= 7.x
* mysql >= 5.0 (or sqlite >= 3.0)
* GTK >= 2.8

Most of the changes made for 0.7.1 have focused on improving the internal APIs 
introduced with 0.7.0. Users should expect to see noticable improvements in 
stability and performance as well as minor visual and functional 
improvements. Developers should note that various APIs have changed quite a 
bit, in particular the file-sharing APIs and gnunetutil. 

Noteworthy improvements since GNUnet 0.7.0e include: 
* Files from stopped downloads are deleted
* Improved logging capabilities
* Guile-based gnunet-setup
* gnunet-setup GTK interface is now based on glade
* Improved database performance
* FSUI upload and unindex operations are now persistent
* FSUI API allows clients to associate handle with all persistent operations
* Cleaner abstractions should make porting GNUnet easier
* Improved OS X, BSD and Solaris portability
* gnunet-gtk now disables buttons that cannot be used