Use JUBAUTS_PLUGIN_PATH environment variable to load plugin
use absolute path for the values of get_status (fix #634)
add test for jubatus::server::common::real_path
Add empty-mix test for clustering
Fix SEGV on mixing gmm compressive storage
Merge pull request #749 from jubatus/fix-634

Use absolute path for the values of get_status (fix #634)
Merge pull request #751 from gintenlabo/fix-segv-on-distributed-gmm-clustering

Allow empty data for gmm::batch (fixes #750)
space on the end of line
Merge pull request #743 from jubatus/fix-plugin-path

Fix plugin path