Set ASM_FLAGS for 32-bit building on Mac

Build 32-bit version binaries correctly

Changing OS_ID is not enough.

Support cross-compiling for windows using cmake

When building with TCC, it needs to be a cross-compiler, and
present as ${CMAKE_CURRENT_BINARY_DIR}/cross-tcc

To compile for 64-bit windows:
$mkdir build
$cd build
$cmake ../make -DR3_OS_ID=0.3.40 -DCMAKE_TOOLCHAIN_FILE=../make/Toolchain-cross-mingw64-linux.cmake

Fix mold of an Image with length of multiple of 10

If the length of the image is multiple of 10 (e.g. 5x1), mold of it
will be like:

make image! [5x1 #{
RRGGBBRRGGBBRRGGBBRR
GGBBRRGGBBRRGGBBRRGG
BBRRGGBBRRGGBBRRGGBB00
}]

while expecting:

make image! [5x1 #{
RRGGBBRRGGBBRRGGBBRR
GGBBRRGGBBRRGGBBRRGG
BBRRGGBBRRGGBBRRGGBB
}]

The problem is that an extra newline is counted in this case. Only the
newlines between the first and last pixel is needed, if the last pixel is
right at the end of the line, no need to count it here, as it will be
appended later.

Bump version to 3.0.99

Bump version for 3.1 beta

Fix build brokenage caused by ffi merge