* adding scipy integrate, initial check-in
* compile unix double-precision, select integrations algos
* bumping ulab version number to 6.7.0
* adding documentation
* documentation fix
* documentation fix
* documentation fix
* rewritten in some places
* complex number error handling
* added test cases
* resolved importing scipy.integrate
* resolved importing scipy.integrate #2
* build integrate only when we have MICROPY_FLOAT_IMPL_DOUBLE
* reverting commit a4c0c0b
* re-pushing failed commit
* Revert "re-pushing failed commit"
This reverts commit a10e89fe14.
* improve tests using math.isclose()
* enabled fp32 builds
* removed conditional includes
* adapted to new function names, corrected importing
* function names similar to in CPython scipy.integrate, some minor corrections
* major rewrite representing the name changes, mapping to CPython scipy.integrate, more background info
ulab not compatible with enabling '_thread' module from the make command :
- building ulab with thread enabled in MicroPython :
`$ make -j8 CFLAGS_EXTRA='-DMICROPY_PY_THREAD=1' BOARD=PYBV11 USER_C_MODULES=../../../ulab all`
yields a firmware with '_thread' module but without 'ulab' module, because 'CFLAGS_EXTRA' is used in the make command and in 'ulab/code/micropython.mk', so the value of the last is ignored;
- the solution is to use 'override' and '+=' in in last line of 'ulab/code/micropython.mk' :
`override CFLAGS_EXTRA += -DMODULE_ULAB_ENABLED=1`
