MSVC allows backslashes and case-insensitive include paths, which causes build failures on other compilers. This commit: - Converts all include backslashes to forward slashes. - Fixes capitalization mismatches to match the actual filesystem.
This reverts commit 7074f35e4b.
7074f35e4b
This is one of the first commits in a plan to remove all `using namespace std;` lines in the entire codebase as it is considered anti-pattern today.