[Ecls-list] Build fixes for the git "master" branch.

[Samium Gromoff]

Good day folks,

The master branch of git://git.feelingofgreen.ru/ecl is tipped off
the juanjo's tree and contains build fixes for both MSVC and mingw,
as well as a couple of other fixes.

  -  The MSVC fix is for the threaded build, where the environment
     structure was marked during GC, but wasn't allocated via it,
     causing a SIGSEGV/retry deadlock.
  -  The mingw fix is a trivial "don't build documentation" one.


regards, Samium Gromoff