Fixes to code coverage build.

1824 fix memory wrapping bug and add unit test cases

Elementary OS support added

Fix for eos #2160

Eosio build darwin, boost version verification

Eosio build: 7 gigs of ram requirement and other fixes

Merging master to avoid conflicts

Merging master before creating PR

Update resource_limits_private.hpp

#2284 validate threshold > 0 for authority, add test case

fix for eos #2364

add unit test case for #2193(double billing)

Docs clearly state this is not a safe call from a signal handler.

Merging master

bancor has wrong README

Error out when no .git directory exists

p2p memory leak fix

This is needed so that boost test framework doesn't steal the SEGV handler from WAVM

Fix nodeos tests to work on arch linux

Fix txn_test_gen's nonce generation (again)