# Functions
AvatarLink returns relative avatar link to the site domain by given email, which includes app sub-url as prefix.
create a time limit code code format: 12 length date time string + 6 minutes string + 40 sha1 encoded string.
EllipsisString returns a truncated short string, it appends '...' in the end of the length of string is too large.
EncodeMD5 encodes string to md5 hex value.
Encode string to sha1 hex value.
FileSize calculates the file size and generate user-friendly string.
GetRandomString generate random string by specify chars.
HashEmail hashes email address to MD5 string.
Int64sToMap converts a slice of int64 to a int64 map.
Int64sToStrings converts a slice of int64 to a slice of string.
IsLetter reports whether the rune is a letter (category L).
IsTextFile returns true if file content format is plain text or empty.
http://code.google.com/p/go/source/browse/pbkdf2/pbkdf2.go?repo=crypto FIXME: use https://godoc.org/golang.org/x/crypto/pbkdf2?.
StringsToInt64s converts a slice of string to a slice of int64.
Subtract deals with subtraction of all types of number.
TimeSince calculates the time interval and generate user-friendly string.
TimeSincePro calculates the time interval and generate full user-friendly string.
TruncateString returns a truncated string with given limit, it returns input string if length is not reached limit.
verify time limit code.