v1.1.7: Sanitize R16P exploitation
Sanitize R16P exploitation: if R16P is activated (at compile time) then the default real kind `R_P` and all its *attributes* are escaled to `R16P` kind, otherwise the R8P is used. Currently, there is not an automatic way to escale `R_P` to `R4P` (but this seems to be a very unusual choice). Stable release, fully backward compatible.