add --resume option to osm import-history
reuse FindTreeChild command while looking for way nodes
prepare FindTreeChild with current head tree to avoid multiple lookups
Do not load all buckets to compute the final tree size/num trees.

RevTreeBuilder.normalizeToBuckets() performance optimization to avoid loading all the
buckets that compose the tree unnecessarily to compute the final tree size and number
of subtrees, but instead pre compute the deltas out of the changed buckets only.
do now swallow exception in ImportOp
Merge remote-tracking branch 'jdgarrett/revert'
Updated unit tests and implemented rev-parse type verification
Merge remote-tracking branch 'jdgarrett/EmptyTrees' into mergeme
Added basic logger
Refactored logger to use log4j for asynchronous file io and added method intercepting for logging.
Fixed a bug with building diff command in web-api.

Made a parseDouble function based off the already existing parseInt function to avoid running into a NPE.
Merge commit '6a3b4489547c5f37b6547403194bd2fbec8d21d0' into node-test
Merge commit 'b855e5b36fdc876a6279674a3a45a89a58a7377f' into node-test

Conflicts:
	src/core/src/main/java/org/geogit/di/GeogitModule.java
	src/core/src/main/java/org/geogit/repository/Repository.java