record more gabout S4 / R5 types; fix some completion bugs
start working on S4 help
parse slots help and use when appropriate
utility function for getting help from object
various tweaks to completion grabbing
more work on generic help finding
completions for 'options', 'getOptions', 'data'
get help for expressions
remove old, unused code
respect autopopup UI pref
more tweaks for help-from-object lookup
not all datasets come from the datasets package
work on a 'safe eval' to guard against most common side effects
suppress save warnings

This prevents warnings of the form:

    Warning in save(opt, file = filename) :
      'package:stats' may not be available when loading
ensure help_ not visible when created
fuzzy narrowing of completion results
better indentation for multiple lines ending with commas
double indent for function declaration; single for function call
missing commits for options help
try harder to resolve object signature