Prevent memory access errors in many native calls by adding checks

[timmc]

This is not comprehensive coverage, but should take care of a number of
unguarded calls. It comes out of issue #81 in which a call to
cryptoSecretStreamPush with an incorrectly sized array lead to a VM
crash.

• Add array checkers to BaseChecker
• Simplify some existing checks by moving the throw into the check
  method; add reporting of which variable failed a check
• Add checkers for SecretStream
• Split PwHash.Checker.checkAll into individual check calls to reduce
  chance of positional argument errors

[timmc]

Tests fail on a call to sodiumPad, but I think the test may be wrong: https://github.com/terl/lazysodium-java/blob/f7f0025/src/test/java/com/goterl/lazycode/lazysodium/PaddingTest.java#L19-L23

Shouldn't the max buffer length always be less than or equal to the length of the buffer?

[ionspin]

@timmc I haven't checked in a while, but I think sodiumPad is still broken, details are in #85

[timmc]

For reference, the ./gradlew test currently produces this test failure:

java.lang.IllegalArgumentException: Provided buffer array length is larger than array
	at com.goterl.lazysodium.utils.BaseChecker.checkArrayLength(BaseChecker.java:59)
	at com.goterl.lazysodium.utils.BaseChecker.checkArrayLength(BaseChecker.java:50)
	at com.goterl.lazysodium.LazySodium.sodiumPad(LazySodium.java:186)
	at com.goterl.lazysodium.PaddingTest.pad(PaddingTest.java:22)