Remove the explicit -O3 parameter to nasm in visual studio project files

According to "nasm -h", there is no -O3 parameter at all, and
the highest optimization level (-Ox) is already the default.

The corresponding parameter never was set when building with the
make build system.
Remove the literal CRLF (&#x0D;&#x0A;) within the nasm commands in msvc project files
Merge pull request #646 from mstorsjo/cleanup-msvc-nasm

Clean up the nasm commands in the MSVC project files