Pavel P

these fixes were [merged long time ago](https://github.com/powturbo/TurboPFor-Integer-Compression/pull/82/commits/9f589445667e688d01305a7e8c735baa28d2686e), but were somehow reverted

Allows testing different coders with different levels: 

added this to usage: 

Note: after I did the change I noticed the code for `-E` param to handle exactly the same stuff I did. So, I updated the PR to only show the...

this PR fixes compilation errors: ``` lib/ext/rc.c:79:10: fatal error: ../bitpack.h: No such file or directory 79 | #include "../bitpack.h" | ^~~~~~~~~~~~~~ ```

Here's how it used to look like when you build/run from visual studio:  this is how it looks like after the PR: 

I reported and fixed some bugs, luckily I added unit tests in my code to verify this mess won't happen again. Sure enough, with latest code the bugs are back....

what a trainwreck, @powturbo what's the reason almost all header guards were removed

@ordinaryorange I have my own wrappers, but you can see the idea from the code: ``` #undef NDEBUG #include "gtest/gtest.h" #include "util.h" #include "coders.h" uint32_t rand32(); static void testCoder(const coders::IntegerCodec&...

> I personally think think this project is an excellent compilation of integer and floating point algorithms, I've not found anything close to the sheer extent of functions on offer,...