- extract_startdat: locate STARTDAT at PSAR + p1 (the u32 at PSAR+0x0C)
instead of popstation's p1 + 0x50000 absolute offset, which only worked
for bases whose PSAR was aligned to 0x50000. Any PS1 classic can now be
used as a base.
- _warn_old_base: print a warning when the base PBP is a 3.xx-era classic,
since its POPS loader often fails to link on 6.60/6.61 CFW (error
80020148 'game could not be started').
- README: document the 6.60/6.61 base preference and DEFLATE compression.