Merge pull request k0kubun#13 from k0kubun/coloring_switch

escape sequences to pipe

Merge pull request k0kubun#12 from k0kubun/fold_large_buffer

Fold a large buffer

Merge pull request k0kubun#11 from k0kubun/print_time

Implement time.Time pretty printer

Merge pull request k0kubun#10 from motemen/quote-string

Color escaped characters inside strings

Don't check nil as visited

`nil` can appear in many places regardless of circular reference.
When pointer is `nil`, uintptr's value is 0.

Write API document

Merge pull request k0kubun#3 from kyokomi/hotfix/infiniteloop

fix: `Fprintln` infinite loop bug.