Allow other nav implementations (like full-ack)

[GoogleCodeExporter]

What steps will reproduce the problem?
1. (require 'nav)

What is the expected output? What do you see instead?
A message of error would display because ack.el couldn't be loaded. I use 
full-ack which provides the required ack function,

What version of the product are you using? On what operating system?
HEAD

Please provide any additional information below.
Even that the error message is displayed, because full-ack provides the 
required ack function the 'a' keybinding works as expected... so the only 
problem is the misleading error message.

Perhaps (featurep 'full-ack) would do the trick?

Using full-ack instead of the embedded version included right now would be 
better. BTW, full-ack is included in elpa.

Original issue reported on code.google.com by rlazo....@gmail.com on 25 Mar 2012 at 2:53

[GoogleCodeExporter]

OK, I checked in a fix.

Original comment by issac.tr...@gmail.com on 1 May 2012 at 5:14

[GoogleCodeExporter]

Original comment by issac.tr...@gmail.com on 1 May 2012 at 5:14

• Changed state: Fixed