* master:
  Add contribution guidelines.
  Add more changes to README.

* master:
  Run integration tests against 3.2.16 (#24)

Create a new method to drop all the indexes of a collection
in a single call

fix [#484](https://github.com/go-mgo/mgo/issues/484)

Annotate connections with metadata provided by the
connecting client.

informations send:

{
 "aplication": {         // optional
   "name": "myAppName"
 }
 "driver": {
    "name": "mgo",
    "version": "v2"
  },
  "os": {
    "type": runtime.GOOS,
    "architecture": runtime.GOARCH
  }
}

to set "application.name", add `appname` param in options
of string connection URI,
for example : "mongodb://localhost:27017?appname=myAppName"

* docs: elaborate on what appName does

* readme: add appName to changes

Fix #30.

Thanks to @feliixx for the time and effort.

* Stop all db instances after tests (go-mgo#462)

If all tests pass, the builds for mongo earlier than 2.6 are still failing.
Running a clean up fixes the issue.

* fixing int64 type failing when getting indexes and trying to type them

* requested changes relating to case statement and panic

* Update README.md to credit @mapete94.

* tests: ensure indexed int64 fields do not cause a panic in Indexes()

See:
* #23
* https://github.com/go-mgo/mgo/issues/475
* go-mgo#476

- Allow specifying the default collation for the collection when creating it.
- Add some documentation to query.Collation() method.

fix #29

* test against MongoDB 3.4.x

* tests: use listIndexes to assert index state for 3.4+

* make test pass against v3.4.x

  - skip `TestViewWithCollation` because of SERVER-31049,
    cf: https://jira.mongodb.org/browse/SERVER-31049

  - add versionAtLeast() method in init.js script to better
    detect server version

fixes #31

* Adds missing collation feature description (by @feliixx).
* Adds missing 3.4 tests description (by @feliixx).
* Adds BSON constants description (by @bozaro).
* Adds UTC time.Time unmarshalling (by @gazoon).

readme: add missing feature descriptions / credit

Fixes #43

* Fix GetBSON() method usage

Original issue
---

You can't use type with custom GetBSON() method mixed with structure field type and structure field reference type.

For example, you can't create custom GetBSON() for Bar type:

```
struct Foo {
	a  Bar
	b *Bar
}
```

Type implementation (`func (t Bar) GetBSON()` ) would crash on `Foo.b = nil` value encoding.

Reference implementation (`func (t *Bar) GetBSON()` ) would not call on `Foo.a` value encoding.

After this change
---

For type implementation  `func (t Bar) GetBSON()` would not call on `Foo.b = nil` value encoding.
In this case `nil` value would be seariazied as `nil` BSON value.

For reference implementation `func (t *Bar) GetBSON()` would call even on `Foo.a` value encoding.

* Minor refactoring

* development:
  readme: credit @bozaro (#47)
  Fix GetBSON() method usage (#40)
  readme: credit @feliixx (#46)
  fix golint, go vet and gofmt warnings (#44)
  readme: add missing features / credit
  bson.Unmarshal returns time in UTC (#42)
  Introduce constants for BSON element types (#41)
  Test against MongoDB 3.4.x (#35)
  Add collation option to collection.Create() (#37)
  Don't panic on indexed int64 fields (#23)
  readme: credit @feliixx in the README (#36)
  add method CreateView() (#33)
  Update README to add appName (#32)
  send metadata during handshake (#28)
  readme: credit @feliixx for #25 (#26)
  add DropAllIndexes() method (#25)

# Conflicts:
#	README.md
#	cluster.go
#	session.go
#	session_test.go