Add support for serving directly from filesystem

You can now pass `-D directory` to redbean which will serve assets from
the local filesystem. This is useful for development since it allows us
to skip needing to shut down the server and run InfoZIP when testing an
iteration of a lua server page script.

See #97

net/http/http.h

@@ -125,6 +125,8 @@ char *DecodeLatin1(const char *, size_t, size_t *);
 bool IsValidHttpToken(const char *, size_t);
 char *EncodeHttpHeaderValue(const char *, size_t, size_t *);
 char *VisualizeControlCodes(const char *, size_t, size_t *);
+char *IndentLines(const char *, size_t, size_t *, size_t);
+bool IsAcceptableHttpRequestPath(const char *, size_t);
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */