Use ' instead of " where not using interpolation
Code style
Refactor Page Purger

- Remove logic from the constructor, so that it only, well, constructs.
  A call must be made to #purge to actually run the purging of that
  page.
- Pull resource definitions out of #find_resources and into the class
  definition
- Bring sanity to the line-endings in the log output; they went haywire
  after we switched to the proper logger
- Massively improve the relative URI handling by using URI.join rather
  than my previous homegrown solution
- Generally make things a bit more OO (e.g. making it so that we're not
  constantly passing URLs as messages but storing them on the instance
  instead
Refactor Spider

- Remove logic from the constructor; it's now necessary to call #run
  after initializing the spider to actually kick off the spidering
  process.
- Extraction of lots of functionality into methods, including the
  previously enormous find_links method
Refactor Purger

- Pull actual purging logic into a new Purger class
- Break logic for determining whether to PURGE or DOMAINPURGE into their
  own methods
- Tidy up TCPSocket call to use a block, so that we get implicit close
Merge pull request #11 from robmiller/fix/code-cleanliness

Code style and refactoring

Fixes #9, #10