Added language's constants

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Reformated

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Automatic indexing of created node in parent's index.

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Getting methods are memorized.

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Moved constants from language to constant collection.

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Testing fact for automatic indexing of created language's node in
parent's index

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Local memorization of node's/relation's database operations

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Changed fact to reflect memorized functions

Signed-off-by: selmeci <selmeci.roman@gmail.com>