Figured out how to draw math formulas in android(by using jqmath and a
WebView).
Made the WebView a bit faster.
Added appache commons math library.
Refactored simple math challenge to use the WebView.
Made challenge for computing the determinant of a matrix.
Finnished the matrix challenge.
Improved layout of MatrixChallenge.
Cleaned up some.
Got DifferentiationProblem problem working. For the time being it only
generates very simple functions.
Added a math challenge where you prime-factorize a large number.
Added math challenge for finding the gcd of two numbers.
Improved design of math challenge.
Made the equations rendered by DifferentiationProblem look better.
Now DifferentiationProblem generates more complicated nested
functions(those that can be derivated using the chain rule)
using abs, sqrt and exponentiation.
strings.xml formatting and clean up
Merge branch 'hard_math_challenge' into development

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Merge branch 'development' of https://github.com/Hasselmannen/sleepfighter into development

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Added licenses.
Localized snooze strings.
Localized some more strings.