A first pass at documenting build plugins

Documentation for the CompileStep is only in the source right now
Allow CompileStep#addAsset to accept Strings for content
Fix bug where backcompat for registerBuildPlugin didn't work
Document packageName
Document Buffer or String argument in addAsset
Add newlines between CompileStep methods
Consistently name path variables
Fix link
Add fullInputPath to public API
Document arch

Fix documentation typo
Rename appendDocument to addHtml
Rename back pathForSourceMap
Fix a big typo
Fix incorrect packageName docs
Fix the failing logging file parsing test on FF
Pass through 'bare' option to compiled js source files
Add note about changing file paths for static assets.

This has bitten several people already. Better late than never.
Also note path changes in the built bundle.
Cleanup Console code, and make sure we cleanup the poller on exit

Not cleaning up the poller was preventing 'meteor mongo' from exiting cleanly
Add link to Wiki, add warning that comments aren't used