Remove most of useless underscores.
Support polynomial rings over semirings.
Close $compiler_output_stream.
Misc cleanups.
Simpler and faster join.
Skip documentation handling in bootstrap mode.
Correct typo from 1104.
Fix problem with conditional exports from category with no principial ancestor.
Omit unused argument to mkCategory.
Make '**', '^' and '->' right-associative ins Spad compiler.