add LZW compression to MongoObjectDatabase
added bulk putAll

Reduces import of wsa_rivers from 327 to 176 seconds
Added paralellization to mongo objectdb putAll

reduces import of wsa_rivers from 176 seconds to 73
Upgrade mongo-java-driver from 2.12.1 to 2.12.2
Update local refs after pushing
Merge duplicated code for printiing fetch results between fetch and pull
Make DiffCount more fine grained
Use DiffCount to get faster pull stats
Upgrade to com.google.code.findbugs:2.0.3
Merge remote-tracking branch 'groldan/mongo_improvements'
A couple fixes to JEGraphDatabase that prevented pushing from sparse clones.

map(ObjectId, ObjectId) was throwing an error if the "mapped" object id
didn't exist, instead of creating a new one.

ObjectIdBinding.entryToObject() was returning null instead of ObjectId.NULL
leading to an NPE's when NodeData.mappedTo was not expected to be null.
Merge branch 'master' of https://github.com/boundlessgeo/GeoGit
Fix bug in PushOp. It was updating local remote refs without the remotes prefix.
Add transparent gzip encoding to web-api request and responses
Merge pull request #770 from groldan/remotes_gzip_encoding

Add transparent gzip encoding to web-api request and responses
Merge branch 'master' into serial_factory_v2

Conflicts:
	src/core/src/main/java/org/geogit/remote/HttpUtils.java
Use regular WKB geometry encoding until GeometrySerializer is ready.
update (c) headers on new files