make help() support an io parameter
move catchall to end
Merge pull request #6257 from one-more-minute/help-io

Extend help() to support an io parameter
allow newlines after 'import X:'

For example,

    import Base:
        read,
        write
Fix #6281
Merge pull request #6296 from amitmurthy/amitm/shmemfix

Fix #6281