Casting function as introduced Fixes #8
extra paranthesis removed @vjovanov
First test for nbody/offset_momentum @vjovanov

This test can be executed successfully, but when uncommenting line 116, it gives an AssertionError. 

If we change the left hand sides at lines 115, 116, 117 to simple variables (not vector updates), it passes too.

Looks like multiple vector updates cause problems. Weird...
SimpleTest2 added for offset_momentum

This test also fails with an AssertionError. I cannot find a reasonable explanation for now.
added test file to test function "advance"
Test deleted as we cannot run it for now @vjovanov
Test for offset momentum deleted as we cannot run it for now @vjovanov
Test for offset momentum 2 deleted as we cannot run it for now @vjovanov
OffsetMomentum-Test deleted as we cannot run it for now @vjovanov
Test Temp deleted as we cannot run it for now @vjovanov
Merge pull request #9 from relite/Introducing-new-casting-function

Casting function "as" introduced - it Fixes #8 - review by @vjovanov - merged