Issue #16038: CVE-2013-1752: ftplib: Limit amount of data read by
limiting the call to readline().  Original patch by Michał
Jastrzębski and Giampaolo Rodola.
#19238, #19289: fix description of the align and fill values of the format specification.
#8964: fix platform._sys_version to handle IronPython 2.6+.
#19319: fix ctypes docs: sizeof is an operator in C, not a function.