* Remove dead code in idl_gen_rust
* Use 2space indentation in mod.rs
* use In/DecrementIdentValue in idl_gen_rust
Fix some whitespace too in generated code.
* make default fn 2space ident
* More 2space formatting
* git clang format
* make vs2015 happy
Co-authored-by: Casper Neo <cneo@google.com>