Improved search

Improved search by adding the ability to specify extra arguments that
will be passed through directly to grep
Added ability to show drafts

This assumes the drafts name starts with "draft-"

fixes bfontaine/rfc#2
Simplified searching

The extra arguments passed to grep are now passed directly, instead of
taking the extra detour through GREP_EXTRA_ARGS
Removed duplicate argument from search
Merge pull request #6 from ecksun/master

Improved search and draft searching