Merge pull request apache#23 from sven0726/2.2-xspark

fork from apache spark branch-2.2

.gitignore

@@ -20,17 +20,6 @@ hs_err_pid*
 *.so
 
 # Folders
-_obj
-_test
-bin/
-pkg/
-.idea/
-sparkTemplate/target
-sparkTemplate.v2/target
-sparkTemplate.v2/driver/target
-sparkTemplate.v2/plugins/target
-sparkTemplate.v2/sdk/target
-!src/github.com/coreos/etcd/pkg
 
 # auditlog folders
 

CONTRIBUTING.md

@@ -0,0 +1,16 @@
+## Contributing to Spark
+
+*Before opening a pull request*, review the 
+[Contributing to Spark guide](http://spark.apache.org/contributing.html). 
+It lists steps that are required before creating a PR. In particular, consider:
+
+- Is the change important and ready enough to ask the community to spend time reviewing?
+- Have you searched for existing, related JIRAs and pull requests?
+- Is this a new feature that can stand alone as a [third party project](http://spark.apache.org/third-party-projects.html) ?
+- Is the change being proposed clearly explained and motivated?
+
+When you contribute code, you affirm that the contribution is your original work and that you 
+license the work to the project under the project's open source license. Whether or not you 
+state this explicitly, by submitting any copyrighted material via pull request, email, or 
+other means you agree to license the material under the project's open source license and 
+warrant that you have the legal authority to do so.