Remove "uncrawlables" naming convention

[dcwalk]

From convo in #16 @b5:

Consensus is forming that our "uncrawlables" phrasing is a problem (@ebarry would also like to drop the uncrawlables phrase), and there are others that are worth considering. This a carry over from our Data Rescue work, and I'm totally down to change it. I'm hoping the next PR on this repo will be refactoring naming conventions, but I want to first write a glossary of terms (on a technical level) and then start a discussion from there about changing naming conventions moving forward.

[mhucka]

As far as a replacement for the term "uncrawlable" is unconcerned, here are some possible starting points. (Not saying these are good, just trying to start the creative process going!)

• inaccessible
• unharvestable
• unparseable
• uninterpretable
• unspiderable