Improved engine version compatibility

[S-S-X]

Changed:

• Better compatibility with different engine versions.
• Coverage / debug dynamic hooks for better performance.

Somewhat related issues:

• Onboarding / Howto / Readme #4
• Ability to select Minetest API version #7
• Dependency system for Mineunit modules #38
• Allow running in strict mode #64

[github-actions]

Click for detailed source code test coverage report

Test coverage 47.51% in 28/38 files:

File                                      Hits Missed Coverage
--------------------------------------------------------------
game/constants.lua      12   0      100.00%
voxelmanip.lua          214  2      99.07%
game/privileges.lua     64   3      95.52%
settings.lua            372  19     95.14%
craftmanager.lua        119  13     90.15%
assert.lua              200  32     86.21%
core.lua                87   21     80.56%
auth.lua                39   10     79.59%
craft.lua               93   24     79.49%
itemstack.lua           121  34     78.06%
entity.lua              64   20     76.19%
player.lua              301  115    72.36%
metadata.lua            177  80     68.87%
config.lua              63   35     64.29%
globals.lua             87   49     63.97%
game/features.lua       21   12     63.64%
fs.lua                  5    4      55.56%
common/serialize.lua    55   44     55.56%
init.lua                118  97     54.88%
game/register.lua       185  179    50.82%
common/vector.lua       70   73     48.95%
world.lua               82   86     48.81%
game/auth.lua           38   68     35.85%
common/misc_helpers.lua 148  269    35.49%
game/misc.lua           42   87     32.56%
game/item.lua           142  331    30.02%
lib/json.lua            51   146    25.89%
deprecation.lua         3    12     20.00%
server.lua              0    150    0.00%
scwd.lua                0    1      0.00%
protection.lua          0    12     0.00%
print.lua               0    66     0.00%
nodetimer.lua           0    35     0.00%
http.lua                0    60     0.00%
game/chat.lua           0    652    0.00%
default/functions.lua   0    354    0.00%
common/chatcommands.lua 0    63     0.00%
common/after.lua        0    26     0.00%

Mineunit stdout:

++ Executing suite spec/assert_spec.lua
++ Executing suite spec/auth_spec.lua
++ Executing suite spec/core_spec.lua🢆 Running tests from core_spec.lua:39 ▷ Mineunit core deprecation prints error
E:	test deprecation message
🢆 Running tests from core_spec.lua:39 ▷ Mineunit core deprecation prints warning
W:	test deprecation message

++ Executing suite spec/craft_spec.lua
++ Executing suite spec/debug_spec.lua
W:	Tests skipped: Debug hooks not available.

++ Executing suite spec/itemstack_spec.lua◌
++ Executing suite spec/metadata_spec.lua
++ Executing suite spec/player_bare_spec.lua
++ Executing suite spec/player_spec.lua
++ Executing suite spec/voxelmanip_spec.lua
231 successes / 0 failures / 0 errors / 1 pending : 4.174341 seconds

Pending → spec/itemstack_spec.lua @ 20
ItemStack constructor fails ItemStack()
spec/itemstack_spec.lua:20: Waiting for strict mode implementation

[S-S-X]

Superseded by #118