bash: Add reverse cycle TAB completion

Make it possible to use SHIFT-TAB to reverse-cycle through possible
completions.

Include a commented out line to automatically display the possible
completions (to be used instead of TAB cycle).

bash/inputrc

@@ -5,10 +5,15 @@
 # Use case-insensitive TAB autocompletion
 set completion-ignore-case on
 
+# Auto list tab completions (use instead of TAB-cycling)
+# set show-all-if-ambiguous on
+
 # Make TAB cycle through possible completions
 "\t": menu-complete
+# Make SHIFT-TAB reverse cycle through possible completions
+"\e[Z": "\e-1\C-i"
 
 # Use the string that has already been typed as the prefix for searching
-# through commands (i.e. more intelligent Up/Down behavior)
+# through commands (i.e. more intelligent Up/Down-arrow behavior)
 "\e[B": history-search-forward
 "\e[A": history-search-backward