Disable warnings on structure members padding.

  `variable' might be clobbered by `longjmp' or `vfork'

  Remove -b from debug-enabled configuration, as Tiny C might have
  been built without the memory and bounds checker support.

  Better disable following warnings when cross-compiling with a gcc older
  than 3.0, to avoid warnings from third party system headers:

    -Wmissing-declarations
    -Wmissing-prototypes
    -Wunused
    -Wshadow

options don't succeed in opening the target file etc. Detected by coverity.com

coverity.com

has already been dereferenced so it is bound to be valid. Pointed out to us
by coverity.com

  Disable following warnings when cross-compiling with a gcc older
  than 3.0, to avoid warnings from third party system headers:

    -Wmissing-prototypes
    -Wunused
    -Wshadow

And on the other hand a message after setsockopt() certainly must use SOCKERRNO.

  Do not enable -pedantic when cross-compiling with a gcc older
  than 3.0, to avoid warnings from third party system headers.

  Highest warning level is double -A, next is single -A.
  Due to the big number of warnings these trigger on third
  party header files it is impratical for us to use any of
  them here. If you want them simply define it in CPPFLAGS.

use the startup of the IPv6 test server as a substitute check for this).

  Warning level reduced from double -A to single -A

_ Update RPG binding accordingly.
_ Fix new options comments.

2) Disable SGI remark: controlling expression is constant

  Due to the HP-UX socklen_t issue it is insane to use the +w1 warning level.
  It generates more than 1100 warnings on socklen_t related statements.

  Until the issue is somehow fixed we will just use the +w2 warning level.