Improve Code Quality

[mschoema]

The functions tpointseqarr_stbox and tnpointseqarr_stbox do the exact same thing and could be merged into a single function.

MobilityDB/src/point/tpoint_boxops.c

Lines 182 to 192 in d4ca7ec

	void
	tpointseqarr_stbox(const TSequence **sequences, int count, STBOX *box)
	{
	memcpy(box, tsequence_bbox_ptr(sequences[0]), sizeof(STBOX));
	for (int i = 1; i < count; i++)
	{
	const STBOX *box1 = tsequence_bbox_ptr(sequences[i]);
	stbox_expand(box, box1);
	}
	return;
	}

MobilityDB/src/npoint/tnpoint_boxops.c

Lines 174 to 184 in d4ca7ec

	void
	tnpointseqarr_stbox(const TSequence **sequences, int count, STBOX *box)
	{
	tsequence_bbox(sequences[0], box);
	for (int i = 1; i < count; i++)
	{
	const STBOX *box1 = tsequence_bbox_ptr(sequences[i]);
	stbox_expand(box, box1);
	}
	return;
	}

This might be possible with other functions, but I didn't check that yet.

[mschoema]

Uniformize the *_make_free functions.

MobilityDB/src/general/tinstantset.c

Lines 200 to 207 in f4f8257

	TInstantSet *
	tinstantset_make_free(TInstant **instants, int count, bool merge)
	{
	if (count == 0)
	{
	pfree(instants);
	return NULL;
	}

MobilityDB/src/general/tsequence.c

Lines 718 to 722 in f4f8257

	TSequence *
	tsequence_make_free(TInstant **instants, int count, bool lower_inc,
	bool upper_inc, bool linear, bool normalize)
	{
	assert (count > 0);

MobilityDB/src/general/tsequenceset.c

Lines 194 to 201 in f4f8257

	TSequenceSet *
	tsequenceset_make_free(TSequence **sequences, int count, bool normalize)
	{
	if (count == 0)
	{
	pfree(sequences);
	return NULL;
	}

[mschoema]

The definition of the function tinstant_to_tinstantset in tinstant.h is a copy of the one in tinstantset.h and should be removed.

MobilityDB/include/general/tinstant.h

Line 81 in d4ca7ec

extern TInstantSet *tinstant_to_tinstantset(const TInstant *inst);

MobilityDB/include/general/tinstantset.h

Line 93 in d4ca7ec

extern TInstantSet *tinstant_to_tinstantset(const TInstant *inst);

[estebanzimanyi]

Solved by PR #201