add a new translation subdirectory in /data
translation tests (WIP)
translation API (WIP)
schema for translation linkage documents. closes #83
add front and back matter search to original data API
first pass at linkage API, heavily based on original API, closes #84
linkage collection indexes
default available languages for linkage
linkage installer
previous commit did not complete addition of linkage-schema to the makefile
linkage api, closes #84
test for translation linkage api, closes #85
add linkage tests to pre-release testing
remove unused translation api
corrections to schema
fix bugs in JLPTEI schematron