Bug#696466: /etc/bash_completion.d/ack-grep wastes 35 ms running ack-grep --help=types

[Anders Kaseorg]

Package: ack-grep
Version: 1.96-2

After fixing the worst offender (#695811), I found that about 15% of my 
bash’s startup time is spent in /etc/bash_completion.d/ack-grep running 
ack-grep --help=types (about 35 ms).  This stuff adds up!

Please consider refactoring the script to compute $__ack_types and 
$__ack_typeopts on first use, or at package build time.  Alternatively, 
move the script to /usr/share/bash-completion/completions/ack-grep with 
Breaks: bash-completion (<< 1:1.90-1), so that it need not be loaded on 
bash startup at all.

Anders