Default faculty was not defined by default.

Also renamed $id_name to $ID_FIELD + documentary comments

# Conflicts:
#	~dev_rating/application/bootstrap.php

Russian constants are moved to twig & RusLang modules.
Functions were renamed to Semesters::load($id) & Semesters::loadAll().

# Conflicts:
#	~dev_rating/application/classes/Controller/Teacher/Discipline/Edit.php
#	~dev_rating/application/classes/Model/Account.php

Moved some functions from Account to Model_Account & Model_Teacher.