Remove Building.configure() from storing stdout and stderr output to a temp file, since these temp files aren't read from anywhere in emscripten codebase(?). In test suite the temp files are stored to a temp dir, and deleted immediately after the test is run. This prevented test suite from reporting build errors to user when the test fails. Related to #694, #695 and #696. Improve error message reporting at the end of a failed configure run.
Output stdout and stderr from external library builds to console only if EMSCRIPTEN_VERBOSE environment variable is defined, to not spam console with information from external tools by default.
better error message
 - temp fix for test_enet
 - added debugging info to websocket backend
 - refactored accept code to automatically setup peers for incoming connections immediately upon connect. previously, this wasn't done until the server called accept, creating a small window of time for peer message events to be lost
 - renamed send_queue to dgram_send_queue just so its purpose is more clear
remove temporary enet fix, and define gethostbyname_r in a header, so that we can be sure at compilation time that it is used in the way it is expected to be (that function has more than one possible signature in various unixes)
Merge pull request #1575 from inolen/accept_fixes

accept fixes
fix gethostbyname_r types
misc in.h and SDL joystick stubs
Use EM_BUILD_VERBOSE instead of EMSCRIPTEN_VERBOSE as the name of the env. variable that controls whether external configure/build libraries are invoked with logging output to console.
disable node stdin fixes due to side effects
Merge pull request #1543 from juj/configure_debug_logging

Configure debug logging.
Merge pull request #1576 from inolen/misc_stubs

misc stubs for in.h and sdl.h
enable test_dlfcn_basic for asm modules
disable memory init file in test_dlfcn_basic
track maximum function index when using dlopen support
do not emit static allocations in side modules
forward parent Module to side module
emit side module memory initializer in the right place; test_dlfcn_basic works in asm
refactor dlfcn test code