SC Book, 3.4
Merge branch 'master' into sc-book
translate actual meaning of Pxrand
SC Book, 3.5
SC Book, 3.5, translation
Merge pull request #126 from namin/sc-book

SC Book, Chapter 3
SuperCollider 3.5 no longer ships with the lin-lin ugen. Therefore, implement it as a cgen.
Merge remote-tracking branch 'origin/master'
simplify and update readme
add missing back ticks
further readme tweaks
Moving mixers into studio.

Starting on the first phase of refactoring synths and instruments.  First
we need to extract setup code from overtone.sc so it is a pure SC interface
API.  Then the Overtone specific stuff, like setting up default groups, mixers,
etc., will go in Studio.

During this I'll cleanup some of these refs and try to get our state more
organized as well.

* moved sc.mixer to studio.mixer
* using a single studio* atom for base state info, rather than a bunch
of refs.
Making native code a bit more reload friendly.

* Putting defclib form inside defonce so we don't redefine the library
each time the file is loaded.

* Cleanup up options form.
Only polling for midi devices once on boot, since they aren't detected afterwards anyway.
Fix docstring inaccuracies
Updating todo items.

* removing finished and irrelevant items
* adding issue regarding synth groups and isolating Overtone setup away from
stuff in overtone.sc
Moving Overtone specific setup from overtone.sc into overtone.studio.

* creation of core groups and mixers now done in studio.mixer

* using overtone.studio.core/studio* atom for studio state,
rather than mix of refs previously used.  These aren't items that
will be modified often, let alone requiring high concurrency, so
this way we have one map for all the studio state.

* The main remaining issue in terms of separating setup code from
SC interface is that synth and group creation, done in sc.node and sc.synth,
both need access to the studio.core/studio* var so they can place groups
and synths in the right location.  Maybe we should make these functions
generic, and create separate versions within studio?
Moving synthdef-decompile to sc.machinery.synthdef.
Fix guitar example
Add helper fn which returns a simple map representing the next modified controller.