Optimise images (249 KB reduction)

Hi, jamesu.

I've taken the liberty of putting rucksack's image assets though a range of optimisation tools. Image optimisation allows us to reduce the footprint of images - meaning faster load times at no cost to image quality. It does this by finding the best (lossless) compression parameters, stripping embedded comments, and removing unnecessary colour profiles. [See more](http://port3000.co.uk/imageoptimiser-a-github-bot-to-proactively-op).

I found 58 optimisable images, making a 249 KB reduction in size. That's about 56.15% of your total image assets.

Merry Christmas.

<table><tr><th>Name</th><th>Reduction</th></tr><tr><td>aac.png</td><td>65.64%</td></tr><tr><td>ai.png</td><td>69.97%</td></tr><tr><td>aif.png</td><td>66.48%</td></tr><tr><td>asp.png</td><td>63.98%</td></tr><tr><td>aspx.png</td><td>62.47%</td></tr><tr><td>avi.png</td><td>59.91%</td></tr><tr><td>bin.png</td><td>60.23%</td></tr><tr><td>bmp.png</td><td>60.26%</td></tr><tr><td>css.png</td><td>62.99%</td></tr><tr><td>db.png</td><td>62.54%</td></tr><tr><td>dll.png</td><td>60.56%</td></tr><tr><td>doc.png</td><td>65.90%</td></tr><tr><td>eps.png</td><td>60.48%</td></tr><tr><td>exe.png</td><td>60.70%</td></tr><tr><td>fav.png</td><td>65.36%</td></tr><tr><td>genericBlue.png</td><td>71.92%</td></tr><tr><td>genericGray.png</td><td>80.06%</td></tr><tr><td>genericOrange.png</td><td>71.83%</td></tr><tr><td>genericRed.png</td><td>72.37%</td></tr><tr><td>genericTurquesa.png</td><td>72.40%</td></tr><tr><td>gif.png</td><td>61.64%</td></tr><tr><td>gz.png</td><td>64.83%</td></tr><tr><td>help.png</td><td>62.12%</td></tr><tr><td>help2.png</td><td>79.93%</td></tr><tr><td>hqx.png</td><td>64.29%</td></tr><tr><td>html.png</td><td>62.65%</td></tr><tr><td>jpg.png</td><td>60.42%</td></tr><tr><td>js.png</td><td>66.41%</td></tr><tr><td>mov.png</td><td>59.32%</td></tr><tr><td>mp2.png</td><td>59.15%</td></tr><tr><td>mp3.png</td><td>64.80%</td></tr><tr><td>mp4.png</td><td>59.02%</td></tr><tr><td>mpg.png</td><td>58.76%</td></tr><tr><td>pdf.png</td><td>62.21%</td></tr><tr><td>php.png</td><td>64.01%</td></tr><tr><td>pic.png</td><td>61.20%</td></tr><tr><td>png.png</td><td>60.30%</td></tr><tr><td>pps.png</td><td>59.01%</td></tr><tr><td>ppt.png</td><td>59.60%</td></tr><tr><td>psd.png</td><td>69.02%</td></tr><tr><td>rar.png</td><td>64.98%</td></tr><tr><td>rb.png</td><td>70.60%</td></tr><tr><td>rtf.png</td><td>67.95%</td></tr><tr><td>tif.png</td><td>61.69%</td></tr><tr><td>ttf.png</td><td>63.16%</td></tr><tr><td>txt.png</td><td>79.32%</td></tr><tr><td>vbs.png</td><td>59.64%</td></tr><tr><td>warning.png</td><td>68.52%</td></tr><tr><td>wav.png</td><td>65.53%</td></tr><tr><td>xls.png</td><td>61.97%</td></tr><tr><td>xml.png</td><td>65.51%</td></tr><tr><td>zip.png</td><td>64.74%</td></tr><tr><td>loading.gif</td><td>42.54%</td></tr><tr><td>rails.png</td><td>6.47%</td></tr><tr><td>12k.png</td><td>45.89%</td></tr><tr><td>50x50.png</td><td>14.12%</td></tr><tr><td>5k.png</td><td>50.79%</td></tr><tr><td>SecurityFramework.png</td><td>49.72%</td></tr></tr></table>

Tools used: advpng, gifsicle, jpegoptim, jpegrescan, jpegtran, optipng, pngcrush, pngout. This is an automated bot maintained by [@skattyadz](https://twitter.com/skattyadz)