The FCGlobal.h can be included in a Global.h header file of an extension module.
The reason is that some IDEs (e.g. QtCreator) fails to detect the export/import macros when only defined in the PreCompiled.h files and thus raise a parser warning.
+ some are doxy others are just comment code.
+ some minor whitespace and grammatical tweaks.
+ app/SCL/* typos have also been submitted upstream (https://github.com/stepcode/stepcode/pull/366). So it's ok to merge them in to master.
