ofToDataPath causing a crash

Hi guys,

Just tried the 0.9.0 released version on Windows 10, VS2015, and got into a crash, which seems to be caused by this line in ofToDataPath() when path is an empty string "".
bool hasTrailingSlash = std::filesystem::path(path).generic_string().back()=='/';

I ran into this while running ofxHTTP. In its FileSystemRoute::handleRequest() function, there is a call to it using an empty string, trying to get the absolute path of the data folder:
Poco::Path dataFolder(ofToDataPath("", true));

It will work if I change the "" in ofxHTTP to ".", but it's probably a good idea to put a check in ofToDataPath() as well.