moved crc and xorshift from DSP to CODE repository

README.md

@@ -0,0 +1,29 @@
+This is a work in progress and a long overdue attempt to bring all our not-DSP-related code together and make it reusable for our future projects.
+
+Before using any of this you should enter the tests directory and execute "make".
+This will check if your compiler is able to create binaries that are able to produce correct results when executed.
+
+What we have included so far:
+
+### [crc.hh](crc.hh)
+
+A [Cyclic redundancy check](https://en.wikipedia.org/wiki/Cyclic_redundancy_check) helps ensuring data integrity.
+
+For example, if we need to integrate CRC32 checking for a few bytes, like in the following:
+```
+# echo -n 'Hello World!' | rhash -C -
+(stdin) 1C291CA3
+```
+We can add it to our project as simple as that:
+```
+DSP::CRC<uint32_t> crc(0xEDB88320, 0xFFFFFFFF);
+for (uint8_t c: std::string("Hello World!")) crc(c);
+assert(~crc() == 0x1C291CA3);
+```
+
+### [xorshift.hh](xorshift.hh)
+
+Sometimes we need a sequence of ["random enough"](https://en.wikipedia.org/wiki/Diehard_tests) numbers but don't want to store them in an array to get a repeatable sequence.
+Here a [Pseudorandom number generator](https://en.wikipedia.org/wiki/Pseudorandom_number_generator) can help by prodiving a deterministic and thus repeatable sequence of numbers.
+[George Marsaglia](https://en.wikipedia.org/wiki/George_Marsaglia) discovered a class of simple and fast pseudorandom number generators, which he called [Xorshift](https://en.wikipedia.org/wiki/Xorshift).
+