Issue #298: Fix compilation on Linux.
Issue #298: Add macros for separator and path separator.
Issue #298: Use macros for separator and path separator.
Issue #298: Rename launch.c and launch.h.
Issue #298: Rename function init() to pyi_arch_setup().
Issue #298: Rename function doIt() to pyi_launch_execute().
Issue #298: Wrap platform specific initialization and finalization code in bootloader.
Issue #298: Move some path functions to pyi_path.c.