Copying tdb code to an indexing backend
Added sanity checks to tdb_record_add
Moved all tdb based indexing code to the backend
Added mapistore_indexing_tdb_init code
new test directory with unittest of openchange code

  * Now it only has unittest for namedprops_mysql.c from libmapistore
  * It uses check framework and cmake for building.
  * It requires to have openchange already installed locally
use markdown for readme file
markdown format
add coverage flags and xml test output