Major code cleanup

This fixes jasperproject/jasper-client#123 and also fixes jasperproject/jasper-client#119. It partly resolves jasperproject/jasper-client#51.

You now should use "client.jasperpath"-module for all path related stuff (instead of hardcoding the strings). There's room for improvement (e.g. put the paths into a config file), but anyhow, this should do it for the moment.

Also, you really need to use the "tempfile"-module, which will create temporary files in the right location (and deletes them afterwards).

Last but not Least: I really don't get all this crazy sys.path-manipulation...what's the deal with that? I removed it for now.

I'll hope you can use these changes.

Fun fact: I did this to make it possible to create a ArchLinux PKGBUILD.
I just tidied up the code...i'm not sure I understand what it *really* does, especially in the case.

It looks like the threshold is calculated like this:
![Threshold calculation](http://latex.codecogs.com/gif.latex?%5Ctext%7BThreshold%20%7Dt%20%3D%20m%5Ccdot%5Cfrac%7B1%7D%7B20%7D%5Ccdot%5Csum_%7Bi%3D1%7D%5E%7B20%7D%5Cfrac%7BRMS_i%7D%7B3%7D)

RMS is the root mean square of the signal, or - if divided by three - the `score`.
The arithmetic mean of `score` (i.e. the `average`) times the `multiplier` seems to be the threshold. So the threshold is basically the average RMS multiplied with 0.6 (= 1.8*1/3).

I have no idea why we're diving the RMS by 3 (when we're comparing with `average` later, that should cancel out anyway).

I also think that the seconds has somehow to do with the 20 frames and probably the sample rate and chunk size. But I really have no idea. I've just taken them from the original code.