Use dynamically loaded HBase compatibility layer

titan-hbase-core now dynamically instantiates one of two
implementations of the HBaseCompat interface depending on what version
string HBase's VersionInfo class reports.  There's one implementation
for 0.94 and one implementation for 0.96.  This approach is directly
inspired by Apache Hive's ShimLoader, which does something similar to
mask minor incompatibilities between different Hadoop versions.

The next critical step in this refactoring would be to write an
assembly that includes all of titan-hbase-094, -096, and -core in one
jar.

The titan-hbase-096 and -094 modules both appear to pass their tests
on my machine.
Merge branch 'bigbang' of github.com:thinkaurelius/titan into bigbang
Additional HBase refactoring

Added a module that builds a frankenjar containing titan-hbase-core
plus a pair of compatibility classes that hide minor API differences
between HBase 0.96 and 0.94.  These compatibility classes are each
compiled against their respective HBase version; core is compiled
against 0.96 by default; they all go in a single jar.

This imports cleanly in Intellij IDEA and Eclipse.
Merge branch 'bigbang' into titan05
Increase log "fuzz test" msg len to 4 MB