Remove custom FindCUDA module, update dependencies

[slizzered]

• The custom FindCUDA module was really getting outdated (produced warnings in newer CMake versions)
• It was once needed for a workaround with Boost 1.55
• Now, Boost 1.55 is not allowed (since it is broken)
• Benefit: we do not have to keep the (ugly!) workaround alive.
• Benefit2: we do not have to maintain and ship our own CMake modules
• People can still use LOWER or HIGHER versions of Boost
• Also some version checks added, since our dependencies did change quite a bit over the last months
• New dependencies updated in README.md

close #61 close #59

[erikzenker]

Wow +13 −2,731 congratulations for the biggest source base reduction of the current week :cake: Time to merge !