Updated some links for changed organization

CONTRIBUTING.md

@@ -15,7 +15,7 @@ For larger features, feel free to create the pull request even before the implem
 finished so as to get early feedback on the code.  When doing this, put the letters "WIP" at
 the start of the title of the pull request to indicate it is still a work in progress.
 
-For new features, consult the [New Feature Checklist](https://github.com/pandegroup/openmm/wiki/Checklist-when-adding-a-new-feature),
+For new features, consult the [New Feature Checklist](https://github.com/openmm/openmm/wiki/Checklist-when-adding-a-new-feature),
 which lists various items that need to be included before the feature can be merged (documentation,
 tests, serialization, support for all APIs, etc.).  Not every item is necessarily applicable to
 every new feature, but usually at least some of them are.

README.md

@@ -1,4 +1,4 @@
-[![Build Status](https://travis-ci.org/pandegroup/openmm.svg?branch=master)](https://travis-ci.org/pandegroup/openmm?branch=master)
+[![Build Status](https://travis-ci.org/openmm/openmm.svg?branch=master)](https://travis-ci.org/openmm/openmm?branch=master)
 [![Anaconda Cloud Badge](https://anaconda.org/omnia/openmm/badges/downloads.svg)](https://anaconda.org/omnia/openmm)
 
 ## OpenMM: A High Performance Molecular Dynamics Library

SUPPORT.md

@@ -1,7 +1,7 @@
 ## How to Get Support for OpenMM
 
 There are two main venues for getting support for OpenMM: the [discussion forum](https://simtk.org/forums/viewforum.php?f=161)
-and the [Github repository](https://github.com/pandegroup/openmm).  There is some overlap
+and the [Github repository](https://github.com/openmm/openmm).  There is some overlap
 between the two, but generally speaking the forum is for user oriented issues while the
 repository is for developer oriented issues.  If you have a question about how to use OpenMM
 (including writing programs that access it through its public API), post on the forum.  If