Bugfix: += and related operators now set the type string properly for primitives. This is done conservatively; if a type is already set, then it is not overwritten.
Merge branch 'var_default' into gm5_compat
Hack: Avoid a costly cout for script-heavy games; added a print_line statement for console output.
GM5 dictates a particular return syntax for string(). Mimicking here --need to check against GM Studio.