Update list for Advanced Bash Scripting Guide
Advanced Bash Scripting Guide 5.7 estimated in January 31, 2010
-alpha release
Advanced Bash Scripting Guide 5.6 forthcoming in December 7, 2009
-5.6 beta release
Advanced Bash Scripting Guide 5.5 from December 1, 2008
New material, updates, bugfixes, stylistic revisions
Advanced Bash Scripting Guide 5.4 from July 25, 2008
Advanced Bash Scripting Guide 5.3 from May 17, 2008
Advanced Bash Scripting Guide 5.2 from March 18, 2008
Advanced Bash Scripting Guide 5.1 from December 31, 2007
Index enhanced, updates, bugfixes, stylistic revisions
