libaltos: don't carry pre-built .dll files in the repo any more

diff --git a/libaltos/altos.dll b/libaltos/altos.dll
deleted file mode 100755 (executable)
index ccdf8c8..0000000
Binary files a/libaltos/altos.dll and /dev/null differ

diff --git a/libaltos/altos64.dll b/libaltos/altos64.dll
deleted file mode 100755 (executable)
index 9bdb8f5..0000000
Binary files a/libaltos/altos64.dll and /dev/null differ