Sponsors and Financial information facilities

Improving the infrastructure to manage Sponsorships and display our financial information

added issue SciPost#144 (closed)

added issue SciPost#189 (closed)

added issue SciPost#193 (closed)

added issue SciPost#214 (closed)

added issue SciPost#215 (closed)

added issue SciPost#218 (closed)

added issue SciPost#229 (closed)

added issue SciPost#248 (closed)

added issue SciPost#282 (closed)