[Lazarus] Mac default widgetset Cocoa

[Mattias Gaertner]

Hi,

The default LCL widgetset under macOS for Lazarus trunk is now Cocoa.
For example a 'make' or 'make clean all' on Mac now compiles a cocoa
IDE.

If you want to compile a carbon target using "make" use:

make LCL_PLATFORM=carbon


Mattias