new local navigation - rotate sections, starting from current section

If we consider a list of local sections ("a", "b", "c", "d", "e"), and current section is "c", than
before
display: ("c", "a", "b", "d", "e")
![screen shot 2014-06-17 at 16 10 44](https://cloud.githubusercontent.com/assets/1492162/3302101/a0877cee-f631-11e3-9f97-6efe800c45b9.png)
after
display: ("c", "d", "e", "a", "b")
![screen shot 2014-06-17 at 16 09 30](https://cloud.githubusercontent.com/assets/1492162/3302103/a82b6442-f631-11e3-9df2-700bcdefd7c6.png)

We will consider the 'before' behaviour for a separate variant, so keeping the logic in a separate Navigation function, localNavWithoutCurrent.