Added support for cache keys that are not hashed via config option READABLE_CACHE_KEYS

[rdiaztushman]

fixes #672

[telephone]

A few things:

1. You forgot to add the "READABLE_CACHE_KEYS" var to hive, with a default of FALSE
2. There's no need for an !empty() check, a simple $this->hive['READABLE_CACHE_KEYS']?$key.'.var':$this->hash($key).'.var' works.
3. "READABLE_CACHE_KEYS" is a bit too long for my taste. I'd prefer "HASH_KEYS" (If used, you'd reverse the hive default to TRUE, and change the ternary operator to suit).

[rdiaztushman]

I was deliberately trying to 1) minimize the number of changes and 2) preserve current behavior. That's why I didn't add the key to the hive (which means I needed to use empty). There is no change in F3's behavior unless you add READABLE_CACHE_KEYS to your config with a value of true or 1.

[rdiaztushman]

Changes keys in the cache from this:

to this:

which makes them much easier to manage in our admin.

[telephone]

I was deliberately trying to 1) minimize the number of changes and 2) preserve current behavior. That's why I didn't add the key to the hive (which means I needed to use empty). There is no change in F3's behavior unless you add READABLE_CACHE_KEYS to your config with a value of true or 1.

Leaving an undocumented variable check in an open source framework isn't the way. When someone browses the source they'd be met with a non-existent key and probably left scratching their heads (as I was when I viewed your commit).

By adding the key to hive, the behaviour stays identical and leaves behind a nicer trail to follow.

I agree with this toggle to switch hash on/off, as I've implemented it in userland code a few times before via Cache::, and it'd be handy for those not well versed with the source.