Support for !$ (args history expansion )

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 )