Added initial structure and test class for a Redit handler
Added redis-server and memcached to travis.yml file.

Initially this was just to add the redis-server service to travis-ci,
but when reading that documentation I saw that memcached was no longer
on by default and added that as well.
Fleshed out the Redis driver.

This fleshes out the driver a bit more. Right now some functionality is
working, but some is not- getting and storing data works for some
datatypes, for instance, but clearing does not quite work.
Corrected indexing bugs that made cached items irretrevable.
Corrected a TTL bug that essentially made items never expire.

The redis handler takes a ttl, but was instead passed a timestamp- a
huge number tha essentially prevented things from being expired.

This commit also prevents items with a negative ttl from being put into
redis.
Tweaked Redis driver and Drivers class to add Redis and improve consistency.
Merge pull request #86 from jhallbachner/redistweaks

Tweaked Redis driver and Drivers class
Added redis extension to Travis-CI Environment

This update handles three things-

1. Creates a "redis extension" installer script.
2. Adds that installer script to the Travis-CI "before_script" config.
3. Adds the needed configuration to the php.ini file to load the redis
extension.
Tweaked the php_setup.sh script for readability
Corrected a bug with the s/host/server changeover.

Just had to update an index on one of the arrays to make sure it said
"server" instead of "host" to match the previous normalization change.
Cleaned up the php extension install script with notifications.
Added basic support for multiple servers.
Added in tests for RedisArray functionality

This tests the Redis driver against multiple backend Redis servers,
which internally uses the RedisArray object to wrap around multiple
servers. This test requires a second redis server on the 6380 port in
order to run.
Changed test suite class heirarchy to make sure all tests ran.

For some reason the class structure before this change prevented the
first redis driver test from running.
Merge pull request #81 from tedivm/redis_handler

[WIP] Redis Driver