Added Faker::Unit for faking Units including metric system and english system

Additional units and metric system could be added.
added french names
Merge branch 'master' into french-stuff
Merge pull request #93 from PapePathe/french-stuff

French Names
Merge pull request #92 from lurraca/master

Added Faker::Unit for faking Units including metric system and english system
Release 1.21.0
Move PhoneNumber's short_phone_number method from class to instance
Colombian identification, driver license is the same as ID
id is an alias of drivers license
Merge pull request #94 from cheef/hotfix/short-phone-number

Move PhoneNumber's short_phone_number method from class to instance
two letter country identifier
put most constants in a plain txt file, and massive indentation cleanup
no need to tweak load path.
more cleanup
no advantage in autoloading.
Merge remote-tracking branch 'sescobb27/colombian'

Conflicts:
	lib/ffaker.rb
support 1.8.x
Release 1.22.0
Release 1.22.1
Add AddressFR (french)