Fix for Issue #912 ($position in repeat directive can't be both first and last at the same time)

[maxmart]

Fix for issue #912 (#912)

Implementation of my suggested fix where three boolean values $first, $middle and $last replaces the $position variable. I also added a test case for single item lists.

[IgorMinar]

this looks good to me. we need to document this as a breaking change, but I'm for merging this into master before 1.0 final

[IgorMinar]

In order for us to be able to accept this change, can you please e-sign the contributors license agreement (CLA). It's quite straightforward:

For individuals (a simple click through form):
http://code.google.com/legal/individual-cla-v1.0.html

For corporations (print, sign and scan+email, fax or mail):
http://code.google.com/legal/corporate-cla-v1.0.html

[maxmart]

Alright, sure thing.
It's done!

[IgorMinar]

hey, sorry - this is taking longer than I'd like it to. we are going to release some other breaking changes in rc10 so I plan to merge this in at that time.

[maxmart]

Sorry, I accidentally pushed to the wrong branch. These last commits are not supposed to be part of this pull request.
I'm kinda new to git, but I'll try to undo the commits.

[maxmart]

As you can see I created a new pull request that references a branch instead of my master branch.