Rewrite patch

Contains the following edits:
* patches now specified as faces and vertices. Less text for patches that share same vertices.
* handles polygon patches
* hyperlinked the github and fex links (clickable now)
* Added `patchOpt` practically very similar in fashion to `surfaceOpts` but more flexible and contains some fixes on top of `surfaceOpts`. Objective is to have one shader/plotType subfunction.
* `m2pgfColormap` more flexible to allow multiple colormaps. This allows to have individually colored faces or (to do) vertices with specific colors, i.e. when cdata is a 3d array (not possible before).
* Added `\usepgfplotslibrary{patchplots}` requirements in standalone and otherwise userInfo notification.

I ran acid test as of 426f62e1f809fc30d90b9ef1ddf0d1ad3b6a30fa tagged as before as 71411657452330cb907401b97c8490a3b13349c7. Both on dropbox.
before: https://www.dropbox.com/s/37ftzbbw1drwjgt/before.pdf?dl=0
after: https://www.dropbox.com/s/dmg7wbuudus4ff6/after.pdf?dl=0
 
An example of patch:

![capture](https://cloud.githubusercontent.com/assets/3731173/4816795/dbd9efa6-5ee2-11e4-9f06-7ee6eb111e80.PNG)

produced with

```matlab
close all
xdata = [2 3; 
         2 3;
         3 4;
         4 5;
         4 5];
ydata = [1 3
         2 4
         3 5
         2 4
         1 3];
zdata = ones(5,2)*10;
cdata = [15 30
         10 20
         10 30
         2   1
         5   30];
p = patch(xdata,ydata,zdata);
set(p,'FaceColor','flat','Cdata',cdata)
```

**Warning**
I will do some extensive testing on merging `surfaceOpts` and `patchOpts` and create proper testfunctions to experiment what patches can do. I expect that I got some things wrong, but this is already enough commits for now. 
@okomarov Well, some parts are quite OOP-like, some are not. Actually everything is procedural with a light sauce of OOP on top (such as the input parser) and I hope to do the same with some other parts (such as the options handling) as well such that we can pull the code into more independent parts. But the major part will likely stay in a purely procedural fashion, I think.