have the help more info link track the current release
adding a changelog

Closes #15
remove whitespace when reading version string from files

Closes #16
add some reset functions to the shell on init

These functions allow for resetting the env and triggering
activation messages.  the `rb` cli now calls a reset function when
activating versions to ensure an activation msg is shown each time
it is executed.

The auto mode `cd` override now just calls the activate function
directly.  It should behave more 'silently' and has no need to reset
the env every time a `cd` happens.

Closes #9
-f option to force a specific ruby version file

This overrides the version file lookup and allows you to specify a
version file without having to cd there first.

Closes #13
Merge pull request #21 from redding/next-release

Next release