Introducting MasterCaches and Buffer perf. fixes

Fixes #115

Squashed commit of the following:

commit 074aa7569e29174e0d79c1fa15a0302bda70027e
Author: Lennart Koopmann <lennart@socketfeed.com>
Date:   Sat Mar 2 21:40:55 2013 +0100

    finished masterbuffers

commit 58ce0b747166e1988a90c96f4d1e935f0202a46a
Author: Lennart Koopmann <lennart@socketfeed.com>
Date:   Sat Mar 2 18:04:57 2013 +0100

    current state of masterbuffer development