Fix some issues, related to visual studio build

Dear colleagues, please, consider these. Sorry for repeats, looks like I've incorrectly formed my previous pull request on this topic.

**Rationales**
* Linker gave me an error without `/bigobj` option.
* The `CMAKE_BUILD_TYPE` variable [is meaningless for Visual Studio](http://www.cmake.org/cmake/help/v3.0/variable/CMAKE_BUILD_TYPE.html), and I propose to leave it unset.
* Generated files could pollute git logs.