Support for !$ (args history expansion )

[cvanfleteren]

Support for bash style arguments history expansion.

For example:

When you just entered:

ls some_dir

And then enter

rm !$ 

the command gets expanded to

rm some_dir

See the ref at http://www.gnu.org/software/bash/manual/bashref.html
This pull request only has support for the short form, if wanted, I can look at supporting the long form.

This was inspired by a jira issue at Karaf ( https://issues.apache.org/jira/browse/KARAF-2070 )

[trptcolin]

Thanks for this! I made one small tweak, changing the exception message to use !$ (the relevant trigger) rather than !#. Let me know if that wasn't just a typo and I just missed the reason for making it !#.