Revert "fix command.c (replace getenv => factory.getenv_i)"

This reverts commit 8f1fcf6c7dccfb37afd4b46a5b65c4a122a3f53e.
fix Segmentation Fault when loading No-Such-Module
fix minivm
Merge pull request #413 from imasahiro/fix_minivm

Renewal Minivm
Merge pull request #412 from tosnoz/libevent_evhttp

Libevent evhttp implemented
Merge pull request #414 from tosnoz/libevent_evhttp

add compile switch for not supported version evhttp_connection_get_bufferevent()
fix coding style
fix build error
add libevent version comparison for support APIs