Unit tests simplification
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Unit tests simplification part 2
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Unit tests simplification part 4
Unit tests simplification part 5
Fix a bug on ST_UpdateZ
Fix #253
Fix st_addpoint on hole
Fix bug on st_removepoint
Clean test
Fix ST_RemovePoint and Rename ST_ZUpdateExtremities to ST_ZUpdateLineExtremities
Update st_reverse3Dline
Add st_snap test refere to https://github.com/irstv/H2GIS/issues/244
Merge remote-tracking branch 'irstv/master' into fix/erwan

Conflicts:
	h2spatial-ext/src/test/java/org/h2gis/h2spatialext/SpatialFunctionTest.java
Fix test
Forgot to clean a test
Merge pull request #268 from ebocher/retrypr

The spatial tests were cleaned.
Two fixes have been done on ST_AddPoint and ST_RemovePoint.
User can now add on point on a hole.
If the user deletes all vertexes of a geometry, the function ST_RemovePoint returns null.

It fixes #258, #261, #262