Remove junk project file
Require Redis 2.6

In particular this allows us to leverage Lua scripting.
Loosen sorting performance test

This one was failing too much to be useful. This gives it a little more
room, and widens the delta since it seems to vary a lot more than the
other performance tests.
Add deprecation support
Add proper API for accessing indexes by name

Deprecates IndexSet#indexes in favor of IndexSet#[]. The latter properly
considers inherited indexes.
Add lookup of multi index values
Prep 2.0.0 release