Start a major rewrite of the internals of the library.

The public API of Predis\Client will be compatible with older releases, but
many of the core internal classes are going to change.

UNSTABLE

@@ -0,0 +1,8 @@
+*** ATTENTION ***
+
+The library code in this branch is currently undergoing a major rewrite and it 
+is marked as UNOPTIMIZED, HIGHLY UNSTABLE and will most likely FAIL from time 
+to time. The internal API is still subject to frequent changes since its 
+design has not been fully finalized yet.
+
+Feedback is obviously appreciated, but use it at your own risk!