new templates for compensation matrices:
- add_compensation.html
- view_project_compensations.html

view_project.html:
- add compensation link and button to add

view_project_sites.html:
- add column for site's compensation matrices

decorators.py:
- add permissions check in require_project_user() for compensation id

forms.py:
- new form CompensationForm

models.py:
- added FileField to save teh compensation file
- override clean in Compensation to save the original filename and the matrix text
- added upload_to function compensation_file_path() for saving files to the filesystem
- added get_compensation_count() method to Project

urls.py:
- new routes for the compensation views

views.py:
- new view: view_compensations
- new view: view_site_compensations
- new view: add_compensation
- new view: add_site_compensation
- new view: retrieve_compensation for downloading the original file