Add better random number generators to core.

Use crypto API if possible (nodeJS, chrome, ...)
If opera browser use Math.random as this is a good
53bit strong random number generator.
Otherwise use Mersenne Twister algorithm.
Make Uuid using new random number generators.
Fix syntax errors
Merge pull request #9 from sebastian-software/features/better-random-number-generator

Add better random number generator, make Uuid using it.