Fixed history-plugin with option --filter-on receiver:action:  does not add action trace for actor account

Build: fixed option behavior

Merging master into eosio_build_symbol

history_plugin: fixing potential integer overflow #3735

Verify definition exists to prevent SEGFAULT

Change to version 1.0.0, also update minimum gcc and clang versions.

Relocate wiki images and remove unused Doxyfile.

Bios boot tutorial: 200,000 accounts

Remove sync test. Functionality covered by other tests.

Fix issue #3740

zero wasm linear memory on memory growth

Changed to better error message for buyram

add custom error messages to secondary index get

fix multiple bugs that were only exercised with malicious blocks

fix llvm dependency from xenial to bionic on ubuntu:18.04

When a WASM grows its linear memory (via the grow_memory opcode) the new freshly accessible memory is required to be zeroed out.

Our binaryen implementation needs a fix for this.

WAVM is more interesting. It relies on a madvise(MADV_DONTNEED) to mark pages such that a subsequent access to those pages would be zero. This works on Linux.. but does not on macOS. It doesn't appear like this zero behavior that Linux performs is anything to do with what POSIX allows so macOS is probably within its rights to not zero memory.

Change the WAVM memory growth to simply memset() on growth. This is a little undesirable because it means the memory will get zeroed twice on Linux (once in the memset and once in the kernel due to the madvise)