Make it a gem

XXX: It's non-functional ATM
Move configurations to a single file

delete unused evernote_config file
fix gemfile

update dependency versions
start using bundler
fix attr_accessors' syntax
fix lambda syntax
git ignore *.gem
use Dir[..] shorthand instead of glob
fix require paths for subdirs
fix 2 more lambda syntax errors
fix Evernote gem dependency
fix Evernote tag conf
remove unused require
fix evernote initialization
simplify folder structure
fix kindle initialization

uses the new kindle-your-highlights gem
fix encoding for magic utf8 chars
fix main class initialization
fix a reference left over from KindeYourHighlights migration
init word sources if properties set

TODO: could ask the sources if they have the properties they need