add Copyright and GPL license into the Header of Python files

addons/account/__init__.py

addons/account/__terp__.py

addons/account/account.py

addons/account/account_analytic_line.py

addons/account/account_bank_statement.py

addons/account/account_move_line.py

addons/account/invoice.py

addons/account/partner.py

addons/account/product.py

addons/account/project/__init__.py

addons/account/project/project.py

addons/account/project/report/__init__.py

addons/account/project/report/account_journal.py

addons/account/project/report/analytic_balance.py

addons/account/project/report/analytic_check.py

addons/account/project/report/analytic_journal.py

addons/account/project/report/cost_ledger.py

addons/account/project/report/inverted_analytic_balance.py

addons/account/project/report/quantity_cost_ledger.py

addons/account/project/wizard/__init__.py