Cygwin configuration script check is out of date.

[WallyZambotti]

The following line taken from configure is used to determine if the environment is Cygwin:

echo "$CC $CFLAGS $TEST_CFLAGS -mcygwin -o $testdir/conftest$$ conftest$$.c 2>>config.log">>config.log

However the -mcygwin compiler flag is no longer supported and does not work.

So this test must fail resulting in compiles using cygwin using incorrect option settings for libtool (if used).

[WallyZambotti]

The uname utility under cygwin can be used to determine if the environment is cygwin.

[JulNadeauCA]

The configure scripts have been updated to no longer include the -mcygwin compiler flag. Thanks!