Fix formatting issues in underscore.coffee documentation (generated html)

Use docco to regenerate documentation for underscore.coffee.
Merge pull request #3146 from phillipalexander/fix-underscore-docs

Fix broken formatting in underscore.coffee docs
fix exit code when using --nodejs option
Fix: support for consumers of the REPL *module* being able to opt into using the global context via option `.useGlobal`.

Note that, at least for now, CoffeeScript's own REPL *CLI* still uses a
non-global context, rendering modules such as `color`, which attempt to
modify the prototypes of JavaScript primitives, ineffective. By
contrast, node's own CLI does use the global context.
Merge pull request #3150 from mklement0/fix-repl-module-global-context-support

Fix: support for consumers of the REPL *module* being able to opt into using the global context ...
Fix some inconsistent indentation

Some places used 4 spaces instead of 2
Merge pull request #3151 from kchmck/master

Fix some inconsistent indentation