Provide support for querying common directories (temp, local, roaming, ...)

Provide cross-platform means for getting default locations for common uses such as:
* user profile related data (e.g., `C:/Users//AppData/Roaming` in windows)
* local application related data (e.g., `C:/Users//AppData/Local` in windows)
* local application with lower integrity level (e.g., `C:/Users//AppData/LocalLow` in windows)
* temporary data (e.g., `C:/Users//AppData/Local/Temp` in windows)
* user data/documents (e.g., `C:/Users//Documents`)
and similarly for Games, Save Games, Music, Pictures, Videos, and Downloads...

Imo this should not (yet) cover/handle querying of locations for specific users, but refer to the current user (the user that started the program) instead.