Try to detect and remove local paths from error messages when generating a ‘search for existing tickets’ URL.

Closes https://github.com/CocoaPods/CocoaPods/issues/2057
[ErrorReporter] Extract pathless_exception_message
[Hound] Remove trailing whitespace
[Spec] Added ErrorReport spec
[Hound] Clean ErrorReport Spec
[Spec] Fix ErrorReport spec
[Hound] Remove errant `puts` from spec
Merge pull request #2080 from segiddins/remove-local-path-from-ticket-search-url

Try to detect and remove local paths from error messages when generating...