added pycrypto to requirements
Added RANDOM_TOKEN_LENGTH and POST_LIFETIME_MAX to config
Created helper module
Created post api blueprint
added extensible JSON encoder
added Post update endpoint
added foreign key for user on post model
made random char pool global and fixed type in privly_URL
added method to format post url parameters
added get user's posts endpoints
added delete user's Post(s) endpoints
fixed route and added flask login import
register posts
post api: abort 403 on invalid post