A very basic caching system
Fixing minor glitch in cache.rb documentation
Merge branch 'master' into basic_cache
Allowing distinct cache instances per API instance
Default cache is now used by default
Cache has now more Ruby-ish methods
fixup! Default cache is now used by default
Add a simple LRU
Add helpers to get or store values
Improve the cache invalidation code

Since the Hash are sorted, some optimization can
be made
Merge branch 'basic_cache'

* basic_cache:
  Improve the cache invalidation code
  Add helpers to get or store values
  Add a simple LRU
  fixup! Default cache is now used by default
  Cache has now more Ruby-ish methods
  Default cache is now used by default
  Allowing distinct cache instances per API instance
  Fixing minor glitch in cache.rb documentation
  A very basic caching system

Conflicts:
	lib/prismic.rb