Broadcasting and new functions

Hi,

Here are the updates I've worked on to support broadcasting. As well as broadcasting I worked on allowing mapreduce functions to work over a specified axis. Also I have added a large number of new functions to the library covering a bunch of domains. My inspiration has been Numpy, so most of the new functions semantics are meant to match those of Numpy. If this isn't the case you can consider it a bug.

Now is the time for name changes if you can think of better names for any of my new functions please go ahead and re-name them. I've also not yet updated the version number.

I should mention so that you can get an idea of my use-case is that the reason I've contributed lots of these updates is because I'm working on a Javascript machine learning library using numeric and porting lots of code from Numpy.

Sorry that some of the commits are so messy. I made lots of changes which I later changed to something else or removed completely so the easiest file to examine might be `numeric.js` in the latest commit. I should have kept a change log but unfortunately I didn't. So here is a change log now. Hopefully I've not forgotten anything.

* Updated pointwise mathematical functions to support broadcasting. Semantics match that of Numpy.
* Updated mapreduce functions to take an optional axis to reduce over.
* Changed interface to `numeric.pointwise` to support broadcasting. New interface is explained in documentation.
* Changed interface to `numeric.mapreduce` to support folding over an axis. Main requirement now is that numeric functions are used, not JS operators. New method of using is also explained in documentation.
* Added `numeric.inf`, `numeric.sup` to documentation. Added `numeric.arginf` and `numeric.argsup`.
* Added `numeric.mean`
* Added `numeric.variance`
* Added `numeric.std`
* Added `numeric.empty`, `numeric.ones`, `numeric.zeros` for Array creation.
* Added `numeric.range`, `numeric.logspace` for Array creation.
* Added `numeric.flatten`, `numeric.reshape`, `numeric.flip`, `numeric.fliplr`, `numeric.flipup`, `numeric.rot90`, `numeric.roll`,  `numeric.wrap`, `numeric.concat`, `numeric.stack`, `numeric.hstack`, `numeric.vstack`, `numeric.dstack` for shape manipulation.
* Added `numeric.slice` and `numeric.sliceeq` for accessing arrays using slice objects
* Added `numeric.mask` and `numeric.maskeq` for accessing arrays using Boolean arrays
* Added `numeric.index` and `numeric.indexeq` for accessing arrays using Integer arrays
* Added `numeric.clip` and `numeric.saturate` functions to clip values to given range
* Added `numeric.when` function to act like pointwise ternary operator `z = b ? x : y`
* Added `numeric.bool` function to cast a JS value to a boolean value `y = !!x`
* Added `numeric.inner` and `numeric.outer`
* Added `numeric.kron`
* Added `numeric.setDiag`
* Added `numeric.pi` and `numeric.e`
* Fixed bug in CSV reading/writing
* Reorganized documentation reference card into sections
* Updated documentation to explain the new functions and semantics.