Log Message:
Import sigscheme version 0.8.0.

SigScheme is a R5RS Scheme interpreter for embedded use.

It features small footprint (64KB in library form on the 'small' configuration)
like SIOD and TinyScheme, low memory consumption (2-words per cons cell),
multibyte characters handling (UTF-8, EUCs and Shift_JIS) and more.

It is mainly developed to be the Scheme interpreter of uim.