fixed Windows scripts based on TinkerPop

[pluradj]

#1242

Fixes for gremlin.bat and gremlin-server.bat based off of the TinkerPop3 versions of those files.

• I tested on Windows 7 and Windows 10 with Cassandra 2.1.13 and Elasticsearch 1.5.2 local on the Windows machine
• I tested OLAP traversals (Gryo-based) against a remote Linux-based HDFS/YARN/Spark cluster
• I tested passing scripts in with gremlin.bat -e
• I tested installing plugins with gremlin-server.bat -i
• I did not test OLAP against a Windows HDFS/YARN/Spark cluster. It became too much trouble to install -- do people really run Hadoop on Windows :)

I included a logback.xml more as an example, but it doesn't get used since the scripts force log4j ahead of it on the classpath.

It would be simpler to pull in the winutils.exe directly into the build, but I imagine that could complicate licensing concerns.

I didn't tackle a conversion of titan.sh to titan.bat with this PR. I'll open up a separate issue for that. Another separate issue would be adding more Titan-specific support for gremlin.bat -v.

[spmallette]

Nice PR. Merging - thanks.