adma: start implementing steering with eights

method described by G.Elko in "A Steerable and Variable First-Order
Differential Microphone Array".
adma: implement steering with eights

until now only an eight is steered toward target direction, need to
implement steering the null to the noise source

add test
adma: add function to admaNullToSphereAndEight

calculates a weighting coefficient for weighted addition of sphere and
eight signals for a given null angle
remove temp files from repository
adma: finish feature steering with eights

write further test cases to test weighted adding with sphere

test output with beampatterns
adma: add configuration key to return dipole signals

returns the dipole signals that are used for steering

feature steering with eights is now considered complete
speechRecognizer: add comment
Merge branch 'admaSteering'

merge feature steering adma with eights (dipoles) described by Gary W. Elko and
Anh-Tho Nguyen Pong in "A Steerable and Variable First-Order Differential
Microphone Array"
tests: add script to run all unit tests at once