PHPT tests - FFTW execute and FFT error measure, constants declaration

1) Must check coding styles

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2) Must check if we could use a "common" file in test cases (common.php), maybe create a test file (phpt) to test this file functions, how it works?

2.1) TODO: comment this file with this informations:

2.2) function angle_diference($a1,$a2,$degree=false)
this function calculate angle 'distance', 
$a1 and $a2 are two angles (float or int)
$degree=false we will use rad2deg and deg2rad functions, $degree=true we only use $a1 and $a2 as angle values

2.3) function check_return_complex(
	$return_array,
	$know_return_array,
	$expected_individual_MAG_AE,
	$expected_individual_PHASE_AE,
	$expected_total_MAG_MSE,
	$expected_total_PHASE_MSE)

$return_array 
is the fft output array value

$know_return_array 
is the fftw expected array value

$expected_individual_MAG_AE
is the max element absolute error of magnitude, in other words $return_array[$i] and $know_return_array[$i] absolute magnitude diference

$expected_individual_PHASE_AE
is the max element absolute error of phase, in other words $return_array[$i] and $know_return_array[$i] absolute phase diference, in this case we use angle diference, considering phase as radian ($degree=false)

$expected_total_MAG_MSE
is the max "total" mean square error of magnitude

$expected_total_PHASE_MSE
is the max "total" mean square error of phase

return string with error, or true

2.3.1)
TODO: must implement an real to complex convert both array to comple if array they have real numbers

2.4) function check_return_real(
	$return_array,
	$know_return_array,
	$expected_individual_AE,
	$expected_total_MSE)

like 2.3, but 
$expected_individual_AE is similar to $expected_individual_MAG_AE and
$expected_total_MSE is similar to $expected_total_MAG_MSE

return string with error, or true

2.4.1)
TODO: must return error "Complex number inside real return array" or "Complex number inside real know array" if $return_array or $know_return_array have a complex number

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3) 002.phpt - i don't know if i done this test file right, i echo many error messages

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4) 003.phpt - just a first step of fft functions error checks, must implement complex functions first