Changing to use version 553 for build_everything sources.
Minor fixes. Removed debugging print statements from error.cpp and changed .method = to .add_target_method() in wxs_test.srp so it works now.
Fixed compiler bug (!) where code position for unary minus was incorrect, affecting error reporting when not-a-number error was raised by unary minus opcode. Other small fixes.
build_everything_cmd.sh patched with Rithvika Devisetti's updates. More robust stddev calculations.
Added missing files.
Updates on Windows for new pause_at_exit() function, better system() implementation and some file separator slash vs backslash fixes.
Many minor updates. Documentation for some new work on Windows (actual changes not checked in yet).
Fixed prefs to not die when prefs file is missing; made "prefs" be default title in prefs files.