Reverting bad update reversion
- Putting back the asked textures instead of current ones
Acid is not renewable anymore
- default:acid_source isn't registered as a renewable liquid anymore
Grass textures fixed
OK, ROLLBACK!
- All the modifications done before 7845fd5f1f1aaa6eb96f27a4236ea0f66ceb8d84 are reverted
- Merged commits from http://github.com/minetest/minetest_game from 10 days ago to today. (concerning default mod)

TODO: Merge the other mods which have been reverted.
      Add all the commits of Ombridride after the 7845fd5f1f1aaa6eb96f27a4236ea0f66ceb8d84 one.

Signed-off-by: LeMagnesium <mg.minetest@gmail.com>
Let's do a step forward
- Commits :
	b0871dfe0fccb604d2c887551d7469b695842faf (Not really because the reverts were done in my last commit)
	c1043f0120430bb57696074a04a8445f9e9e0651
	35a13c8faf3c84941cf13b6717c50144c96fd133
	6679190d44ea8f4a2621f4b9880217ac50878caa
	eae0c1bc2e8b587b265d6cabdfc42c2233f09d1c
	ef566a5fe15060502fe11acd190d7d833ec2af92
	85bd085ab8ddfe4541799b493f57079727d49309
	254ec74625ca711749ccf0c43e5081fb45eb04d4
	99feb28ec3613c4c7587a254c354f5ff4f370021
	d6b270e197780618f35568647dfc4f5f377130c8
	b4a95f223f13275a3bdc7695209163e72973e6fa
	69d4d5dcad4495b997f9ff7f7b1d4f99e7779da4
	d7a5dcbb2922ed6fc5c746ec8ce1891fff107a55
	48dd18d49ae6ba804ae03c3ed54133af493e18c3
	8c2391d5ac94fe334df22b6671715cfffe1a90ec
  Are done again. (Ok, no all of them only those concerning default and reverted mods)

TODO: Still missing the three next commits

Signed-off-by: LeMagnesium <mg.minetest@gmail.com>