Bug fixes & MIS updates - Student Registration

**Functionalities implemented:**

**1) Bug in get_preferred_lang() template tag, not resolved yet.. hence commented.**
 
   - File modified:
   
     1) templates/ndf/page_list.html

**2) Bug in get_group_type() resolved**
 
   - Was giving following 
     - ```Error in get_group_type() templatetag: invalid literal for int() with base 10: '[group-name]'```
     
   - Reason behind this: Type conversion of string into int where string doesn't consists of digits
   
   - File modified:
   
     1) templatetags/ndf_tags.py
     
**3) 'userDashboard' url replaced by 'dashboard' url and it's argument list.**
 
   - Files modified:
   
     1) templates/ndf/course.html
     2) templates/ndf/drawer_widget.html
     3) templates/ndf/event_details.html
     4) templates/ndf/file.html
     5) templates/ndf/group.html
     6) templates/ndf/node_ajax_view.html
     7) templates/ndf/page_list.html
     8) templates/ndf/person_details.html
     9) templates/ndf/theme.html
     10) templates/ndf/theme_drawer.html
     11) templates/ndf/uDashboard.html
     12) templates/ndf/userDashboard.html


**4) templates/ndf/person_create_edit.html**
   - Tabs: Next & Previous button added
     - Using jquery Next & Previous buttons added on each foundation-tab wherever required.
 
   - Tab's navigation setup on Next & Previous buttons
     - CSS and JS code added to navigate foundation-tabs using Next & Previous buttons.
   
   - Nececssary changes in styles (css) and blocktrans tags added
     
**5) templates/ndf/student_create_edit.html**
 
   - Separate template added for creating/editing Student GSystems
   
   - Similar to person_create_edit.html template except positioning of fields
   
**6) views/person.py**
 
   - Provision for default/fallback template added
   
     - That is, it looks for template based on name (stripped, lowercase, replaced space with underscore) of GSystemType; and if exists, that template is used or else the default/fallback template is used
     
     - Example:
       - default_template: person_create_edit.html
       - For Student GSystemtype: student_create_edit.html
   
**7) templates/ndf/html_field_widget.html**
 
   - Nececssary changes in styles (css) for few html-widgets