[ahrs] remove AHRS_UPDATE_FW_ESTIMATOR and ins_x_neutrals
[conf] remove ins_neutrals settings from example and test conf
[math] pprz_algebra_float: convert some macros to functions
[math] pprz_algebra_double: convert some macros to functions
[math] pprz_algebra_int: convert some macros to functions
[math] pprz_algebra_int: convert more macros to functions
[math] convert some trig macros to functions
[math] int32_sqrt as function
[test] update test_algebra
[math] add double_quat_vmult, fixes for nps
[math] cleanup

headers, extern C, etc...
[math] algebra_double functions in c file
[math] algebra_float functions in c file
[math] algebra_int functions in c file
[misc] fix natnet2ivy compilation
[math] use math functions in orientation conversion
[math] wgs84_ellipsoid_to_geoid as function
[math] add missing alias
[test] add math c files
[math] set default PAPARAZZI_SRC