Merge branch 'master' into fullstack_lsm_staging

Step 1/2 in moving all mainstream development to master instead of fullstack_lsm_staging
tree: 29709bb76752cf4f107048d649445a3643d99ee6
  1. .gitignore
  2. algebricks/
  3. hivesterix/
  4. hyracks/
  5. pom.xml
  6. pregelix/