Core tools and resources for the GiellaLT infra

• shared build resources:
  • automake scripts
  • Xerox-style regexes for FST filtering
• other tools and scripts
  • unimorph conversion scripts
  • apertium conversion scripts
  • scripts for evals and statistics
  • create json endpoints for status badges
• core/shared components of developer tools
• stylesheets, schemas and other shared resources