MIS updates - Student registration template


**Functionalities implemented:**
   
**1) Updated: templates/ndf/student_create_edit.html**
 
   - Foundation's data-abide feature applied on click of each tab's Next button
   
     - That is, if all mandatory fields are filled with proper values then only move to the next tab
   
   - Additional check imposed on college's drop-down
   
     - If group's name is matched with any of the college-name within that drop-down, then select that option & disable widget
     
     - Comes into picture when Program Officer is accessing MIS GAPP from it's college group  
     
**2) Updated: templates/ndf/person_create_edit.html**
 
   - Foundation's data-abide feature applied on click of each tab's Next button
   
     - That is, if all mandatory fields are filled with proper values then only move to the next tab
   
**3) Updated: templates/ndf/html_field_widget.html**
 
   - New widget added specifically for email field (by making use of validators field of AttributeType class)
   
     -  input element with email as value of it's type attribute
   
   - Mandatory check added for upload-file widget
   
   - Blocktrans tags applied wherever necessary

**4) Code added for displaying timestamp in log-files when following scripts are used**
 
   - Files modified:
   
     1) management/commands/create_schema.py

     2) management/commands/data_entry.py