Resolve two dependency convergence failures

Prior to this commit, the project had a pair of versions for each of
Mockito and H2:

Dependency convergence error for org.mockito:mockito-all:1.8.5 paths to dependency are:
+-com.thinkaurelius.titan:titan-test:0.9.0-SNAPSHOT
  +-com.tinkerpop:gremlin-test:3.0.0-20141017.175211-940
    +-org.mockito:mockito-all:1.8.5
and
+-com.thinkaurelius.titan:titan-test:0.9.0-SNAPSHOT
  +-org.mockito:mockito-all:1.8.1

[WARNING]
Dependency convergence error for com.h2database:h2:1.3.171 paths to dependency are:
+-com.thinkaurelius.titan:titan-test:0.9.0-SNAPSHOT
  +-com.tinkerpop:gremlin-test:3.0.0-20141017.175211-940
    +-com.h2database:h2:1.3.171
and
+-com.thinkaurelius.titan:titan-test:0.9.0-SNAPSHOT
  +-com.h2database:h2:1.3.172

This commit opts for for the most recent version in each case.
Add profile to disable javadoc lint on JDK 8

This commit is adapted from 3dd7569640e0109b0eacb1258a265c0255c2ba98.
I didn't use `git cherry-pick`, I just copied over the profile
definition.
Removing/tidying some old TP 2.x test code

This commit removes:

* FakeVertex and associated Frames-based test in
  TitanGraphSerialSpeedTest

* GraphGenerator.  This was really just a thin wrapper around the
  power law graph generator in an old alpha version of Furnace.
  TitanGraphSerialSpeedTest continues to use a graphml file produced
  by GraphGenerator a while ago (titan-test/data/v10k.graphml.gz);
  only the generator that produced it is deleted in this commit.

* The alpha Furnace code in titan-test (used only by GraphGenerator)

I shortened "SerialSpeedTest" to just "SpeedTest" in the classes where
it appears.  I also renamed the ludicrously vague "Schema" class used
by the (Serial)SpeedTest to SerialSpeedTestSchema and moved it into
the same package and folder that uses it.  It's now a Groovy class.

I temporarily commented the body and imports of TitanIndexTest so that
I could get titan-test to run its Grooovy compiler.  Then I updated a
couple of imports (e.g. BP 2.5 Vertex is now TP3 structure.Vertex).
The (Serial)SpeedTest groovy code compiles now:

[INFO] --- gmaven-plugin:1.5:compile (groovy-compile) @ titan-test ---
[INFO] Compiled 18 Groovy classes

It probably has runtime failures, but at it shouldn't cause compile
errors or get in the way of updating & compiling other code in
titan-test to TP3.

TitanIndexTest is not modified in this commit.  I only commented it in
my working copy so that Maven would stop choking on it and run the
gmaven-plugin compilation step.