The following functions are deprecated and will be removed from expl3 at 
the end of 2015:

  - \int_to_decimal:n
  - \int_to_hexadecimal:n
  - \int_to_octal:n
  - \int_from_decimal:n
  - \int_from_hexadecimal:n
  - \int_from_octal:n

To replace these, the following functions are introduced:

  - \int_to_dec:n
  - \int_to_Hex:n
  - \int_to_oct:n
  - \int_from_dec:n
  - \int_from_hex:n
  - \int_from_oct:n

In addition, the new function

  - \int_to_hex:n

is introduced. Note that for the creation of hexadecimal numbers, there 
are now separate functions to create lower and upper case letters in the 
output. See also announcement concerning \int_to_base:nn.
Joseph Wright