Issue #31: Fix deprication warning

Removed 'auto'-option and edited command to start Jekyll in the readme.
Issue #32: fix Rakefile

Changed rake task to launch jekyll preview to use subcommand to start serving using the watch-switch.
Issue #42: Run all PNGs through pngcrush

Ran all images in the assets folder through image optimization tool.
(Used Trimage under Ubuntu)
Merge pull request #44 from kiltec/issue-31

Issue #31: Fix deprication warning
Merge pull request #45 from kiltec/issue-32

Issue #32: fix Rakefile
Merge pull request #46 from kiltec/issue-42

Issue #42: Run all PNGs through pngcrush
Merge pull request #47 from icewolfs/master

Issue #43: fav.ico
improved favicon.ico