Small cleanups to MSVC build setup.

Add more MSVC files to .gitignore.
Make all configurations use default floating point model.
diff --git a/.gitignore b/.gitignore
index 3431b2f..d3fc1b8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,3 +31,7 @@
 celt.pc
 celt.spec
 celt/dump_modes/dump_modes
+*.vcxproj.user
+opus.sdf
+opus.suo
+version.h
\ No newline at end of file