Adapt checks and tests to high precision Real.

This is one of the most important merge requests regarding high precision. It contains the changes which I had to make in checks and tests to make them pass. Please have a look. The summary of changes:

1. python doctest module compares commands output by strings. It cannot perform numerical comparison. So I had to disable it for HP in 696e75d7, because it would print errors like: Expected: 2000.0 Got: mpf('2000.0'), where mpf is the python.mpmath.mpf high precision type.
2. Two calls of assertEqual are conditionally (only when HP is used) replaced by assertAlmostEqual in tests/clump.py and tests/core.py, because assertEqual compares numbers to the last decimal place. While single bit corresponds to roughly one-third of a decimal place, so I am surprised that only two such changes were necessary.
3. in checks/checkColliderConstantness.py an interesting development. The bounds are sorted. However when the bounds are equal (same sphere for a different period) it can happen that the order after sorting has some bounds swapped. I added there a very specific check 45a465af, testing for this condition
4. checks/checkLubrication.py and checks/checkLubricationWithRoughness.py were too slow (up to 30 minutes slow). So when HP is used it calculates fewer iterations in 665a678a
5. in checks/checkPolyhedraCrush.py it appears that number of bodies due to crushing depends on the precision used. I am not surprised by this, hence a special check in 24030f98

The commit ff7704d5 is temporary, it is only to simulate presence of HP. Will be reverted upon rebase of !362 (merged) on this MR.