QEL handling - corrected Birrp output handling

Signed-off-by: LK <LK@uni>
Merge branch 'master' of github.com:geophysics/mtpy
utils: edi2ptcrossdata: first try to fix large alpha variations (using modulo 90 and threshold of 10 degrees w.r.t. 90deg ambiguity of strike) - for faster calculation of beta: changed beta method in analysis/pt to avoid repeated call of skew method

Signed-off-by: LK <LK@uni>