Moved some functions from Account to Model_Account & Model_Teacher.

* Model User has constants to check access for pages
* Some routes are moved to separate files (app/routes/api)
* New abstract model Container for complex objects like Discipline & Student (with -> access operator)
* New DeanOffice controller with access checks
* New SQL procedure to get info about students
* Profile page for students (/dean_office/students/127)

1) Now user info stored in session
2) Merge GetAccountInfo & GetPersonalInfo

+ Code refactoring in the AdmStudent controller

* Controller_UserEnvironment is an abstract class, which defines $twig variable, and calls $twig->render in the after() method.
* $twig contains $twig->User variable by default.
* As I have read, it's totally recommended not to use $twig->Variables, so I defined $twig->set([params]) syntax
* Twig supports "fluent interface", so use $twig->set(...)->set_filename();
* Divided DeanOffice/Credits.php & moved part to Handler/

+ new API methods
+ some code refactoring

1. Discipline models have the direct access to fields, for example: $discipline->subjectName, so you don't have to remember them (press ctrl+space). Improves static code analysis. Also, if you make a mismatch, ErrorException will be thrown — this is the most important improvement.

2. There are some operations on disciplines (attach new teacher, transfer discipline to another teacher, an so on), so you can use them: $discipline->attachTeacher(53).

3. Discipline model has array access operators, so you must not convert instances with toArray() method. A common way is:

/* PHP */
$d = Model_Discipline::load($id);
$d['extraField'] = 127;
$twig->Discipline = $d;  // is ok, cause $d is like an array

/* Twig */
{{ Discipline.extraField }}   // call $d->offsetGet('extraField') method

4. Models Faculty, Student, Teachers and Groups have `getDisciplines()` method, and an array of Model_Discipline will be returned.

5. We use camelCase for all fields: in twig, on the PHP level and also in the database.

Also renamed AddDiscipline to Discipline_Create