Remove broken links from testimonials page

Broken links list:
* http://stackoverflow.com/questions/2785029/in-what-areas-might-the-use-of-f-be-more-appropriate-than-c: NotFound
* http://stackoverflow.com/questions/179332/anyone-actually-using-f-in-production: NotFound
* http://cufp.org/users/lawrenceausten: NotFound
* http://saxonmatt.co.uk/2013/04/adopting-fsharp-part-ii.html: NotFound
* [http://docs.cepheis.com/present/Early Warning Indicators.pdf](http://docs.cepheis.com/present/Early Warning Indicators.pdf): NotFound
* http://stevanovichcenter.uchicago.edu/conferences/fp/Program.html: NotFound
* http://www.simontylercousins.net/journal/2013/2/22/does-the-language-you-choose-make-a-difference.html: NotFound
* http://www.compute.dtu.dk/~mire/FSharpBook/keywordindex.html: NotFound
* [http://dnufba.preview.intergen.net.nz/Lists/Events Calendar/DispForm.aspx?ID=279](http://dnufba.preview.intergen.net.nz/Lists/Events Calendar/DispForm.aspx?ID=279): ServiceUnavailable