ContainsAlphabeticCharacters returns true if the provided string 's' alphabetic numbers.

ContainsNoneAlphabeticCharacters returns true if the provided string 's' contains anything other than alphabetic characters.

ContainsNumbericCharacters returns true if the provided string 's' contains numbers.

ContainsWhitespace returns true if the provided string 's' contains any whitespace characters.

compares a hashed password with its plaintext version using bcrypt algorithm.

hashes plaintext password using bcrypt algorithm.

IsAlphaNumeric returns true if the provided string 's' contains both alphabetic and numberal characters.

IsEmail returns true if the provided 'email' contains only the address part of a valid RFC 5322 address.

reads json body into 'dest' make sure the `dest` is never nil otherwise it will panic.

StringLengthInBounds returns true of the provided string 's' is greater than or equal to min and less than or equal to max.

handles common json parsing errors and writes error response.