DateEncoder unit tests
add self parameter to methods, remove unused imports

Netbeans advices
fixes to date test-case
test adaptive scalar encoder
semi-revert: Encoders need to be imported
add tests for CategoryEncoder
use proper self.assert() for unittests2

only assert xxx will not trigger failure, must use self.assertWHATEVER()
add init file..
formating
fix DateEncoderTest

assertSequenceEqual somehow does not work as I expected, use (array1 == array2).all() instead
some imports, etc..
fix CategoryEncoderTest
fixes AdaptiveScalarTest
DeltaEncoder unit tests
unit tests for LogEncoder
rename log.py to logenc.py to avoid name conflict

with math.log
remove unused variables in scalar encoder
ScalarEncoder unit tests
tests for scalar-space encoder
SDRRandomEncoder tests
SDRCategory enc test