Catch and display error when rate limit is exceeded (twitter or embed.ly)

[davidbauer]

should be handled differently, as twitter rate is per hour and user ("try again later"), embed.ly is per month and key ("tell david to open his purse").

[dergraf]

together with a donate-button! ;)

[davidbauer]

we can copy them from here (bottom of the page): http://weeklyfilet.com/