Update license.txt -> LICENSE and replace modified BSD by standard 3-…

…clause BSD.

license.txt → LICENSE

@@ -1,6 +1,6 @@
-AMReX Copyright (c) 2017, The Regents of the University of California,
-through Lawrence Berkeley National Laboratory and the Alliance for
-Sustainable Energy, LLC., through National Renewable Energy Laboratory
+Copyright (c) 2017, The Regents of the University of California,
+through Lawrence Berkeley National Laboratory 
+and the Alliance for Sustainable Energy, LLC., through National Renewable Energy Laboratory
 (subject to receipt of any required approvals from the U.S. Dept. of
 Energy).  All rights reserved.
 
@@ -16,21 +16,21 @@ notice, this list of conditions and the following disclaimer in the
 documentation and/or other materials provided with the distribution.
 
 (3) Neither the name of the University of California, Lawrence
-Berkeley National Laboratory, Alliance for Sustainable Energy, LLC.,
-National Renewable Energy Laboratory, U.S. Dept. of Energy nor the
-names of its contributors may be used to endorse or promote products
-derived from this software without specific prior written permission.
+Berkeley National Laboratory, 
+Alliance for Sustainable Energy, LLC., National Renewable Energy Laboratory, 
+U.S. Dept. of Energy nor the names of its contributors 
+may be used to endorse or promote products derived from this software 
+without specific prior written permission.
 
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 You are under no obligation whatsoever to provide any bug fixes,

README.md

@@ -20,7 +20,7 @@ irrevocable, worldwide license in the Software to reproduce,
 distribute copies to the public, prepare derivative works, and perform
 publicly and display publicly, and to permit other to do so.
 
-License for AMReX can be found at [license.txt](license.txt).
+License for AMReX can be found at [LICENSE](LICENSE).
 
 ## Development Model
 
@@ -48,6 +48,14 @@ Development generally follows the following ideas:
          *Please ensure that your PR title and first post are descriptive,
          since these will be used for a squashed commit message.*
 
+         Please note the following:
+            If you choose to make contributions to the code 
+            then you hereby grant a non-exclusive, royalty-free perpetual license 
+            to install, use, modify, prepare derivative works, 
+            incorporate into other computer software,
+            distribute, and sublicense such enhancements or derivative works
+            thereof, in binary and source code form.
+
   * On the first workday of each month, we perform a merge of
     `development` into `master`.  For this merge to take place, we
     need to be passing the regression tests.