FloatMath.sqrt has been removed from Android SDK 23

[dominicthomas]

The deprecated class has been removed.

"Historically these methods were faster than the equivalent double-based Math methods. On versions of Android with a JIT they became slower and have since been re-implemented to wrap calls to Math. Math should be used in preference.
All methods were removed from the public API in version 23."

http://developer.android.com/reference/android/util/FloatMath.html

The library now needs to use eg. (float) Math.sqrt(pvx_pvx + pvy_pvy);

[Almeros]

Should be updated in TwoFingerGestureDetector.java indeed.

[mariopce]

done in my pull request #32