Preserve osm changeset close time as commit's timestamp
Upgrade maven surefire plugin and parallel test execution settings.

Parallel test execution settings were using the deprecated 'forkMode'. Replaced
by forkCount/reuseForks as recommended by the plugin's documentation.
Add missing 'final' modifier to RevTree.EMPTY and RevTree.EMPTY_TREE_ID.
Reorganize CLI functional tests into general, plumbing, porcelain, and remote.

Helps reduce the build time by allowing maven to run the tests
for the different packages in parallel.
Upgrade Berkeley DB Java Edition from 5.0.84 to 5.0.104
Upgrade compress-lzf from 0.9.8 to 1.0.1
Upgrade JCommander from 1.30 to 1.35
Upgrade logback from 1.0.13 to 1.1.2
Avoid forks for the mongo tests, they all hit the same db
Avoid forks for the oracle and sqlserver tests, they all hit the same db
updated networking doc
Merge remote-tracking branch 'origin/pr/757'
make Java7 de minimum required Java version. Update docs.
Remove the -XX:UseCompressedOops JVM argument in the generated CLI scripts.

The argument was there regardless of compressedoops being the default
on newer 64-bit JVM's because the BDB JE documentation mentioned its
needed anyways for it to correcly estimate cache usage size.
The current version of BDB JE is able to detect the setting even if
not explicitly set:

java -cp ~/.m2/repository/com/sleepycat/je/5.0.104/je-5.0.104.jar com.sleepycat.je.dbi.CompressedOopsDetector
isEnabled(): true

Hence we remove the JVM argument because it causes issues when geogit
is run with 32-bit JVM's and is not needed by BDBJE at least on Oracle JVMs.
Update local refs after pushing
tmp