src/undo.c: undo_insert_text_cb(): removed alloca() call.
src/undo.c: fixed long-standing undo-redo bug.
undo.c: fixed a bug that text was not redrawn on the undo of large text.
removed mbs/wcs functions which are no longer required.
fixed warnings about signedness difference.
compose.c, undo.c: fixed wrong signal connection, modified ruler and toolbar sizing.
Initial import of Sylpheed (GTK2 version).