Configurable file sizes

[neuroscr]

• Session clients needs to allow more than 10mb
  • Desktop needs to read the sapphire/v1/confg storage's max_file_size
  • Mobile needs to read the sapphire/v1/confg storage's max_file_size
• Storage Server OR needs to allow more than 10mb (512k-1MB chunks?)
• Platform server needs config options ( Whitelist mode unit testing improvements, configurable max file upload, and Onion Request fix #44 addresses this)
  • already has limits.default.max_file_size option
• Nodepomf may need a config option (I believe it's limitless atm but need to confirm)