minor README.md text improvements

Revert "Add missing return in socket_cmp_addresses"

This reverts commit 07085fa.

Rename last pico_free to PICO_FREE

remove unused parameter warnings from compilation

Merge branch 'dev' - Release 1.6.0

TCP: socket garbage collector timeout set to 3 seconds

Remove old check from fragments module

Aesthetic fixes. Code formatting.

Moved websockets to picotcp-modules

pico_rand_feed made weak for external pools feeding.