UPDATE: fs_ API bugfixes & vm changes

Hey all,  a new update just went live! This is mostly a bugfix patch but also has a couple of new limitations to be aware of:

• Fixed fs_* APIs returning -1 in many error cases instead of 0 (they can now be properly checked against NULL in the C API)
• WASM host is now initialized with a WASI configuration. This means WASI modules can be loaded, but be aware that this is only for compatibility - the standard filesystem APIs will be unable to open any files, and standard err/output will not be displayed.
• ISO files larger than 700MB are now rejected - this is a new limitation designed to keep games within the limits of a standard CD-ROM
• fs_read/write are now throttled to emulate transfer speeds - the CD can read at 1.5MB/s, and the memory cards can read or write at 16KiB/s. Manage your reads and writes accordingly!