Fix some concurrency issues with script caching in Gremlin Extension.

Should correct #339.
Fixed bad bug given #329.

By using finally, every request had a wait applied to it.  Major slowdowns ensued.  Uncovered via performance tests.
Adjustments to the EngineController to better reset scriptengines. Related to #306

ScriptEngines should not properly reset and reload init scripts on change to rexster.xml.
Update readme.
Fix formatting in changelog.
Add <read-buffer> config to rexster.xml.

Allow for larger request sizes via rexpro.
Add support for REXSTER_HOME when finding rexster.xml #334
Added LinkedDataSail support to Rexster via LinkedDataSailGraphConfiguration
Merge branch 'master' of github.com:tinkerpop/rexster into linked-data
Simplified the API change to GraphConfiguration made necessary by LinkedDataSailGraphConfiguration, which expects a reference to a base Graph
JavaDoc for GraphConfigurationContext
Alter the semantics of the RexsterClient.close().

There is now only one close() method on RexsterClient and other mechanisms for closing have been removed.
Provide a way to stop RexsterClient from retrying #342
Dependency cleanup and Maven Enforcer plugin config
Add configuration for the time interval for checking rexster.xml.
Update changelog.
Added self to Travis notification list
Changed email address in travis.yml
Added dependencies for running Rexster in IDEA, as IDEA does not include provided dependencies in its classpath
Merge branch 'master' of github.com:tinkerpop/rexster