- added stubs for tcgetattr and tcsetattr
 - added fixes for tty get_char in the node environment
 - added tests for tcgetattr / tcsetattr
 - made test_stdin async to work in the node environment
 - clearerr should reset both eof and error indicators
 - fgetc was incorrectly setting the eof indicator. in cases where fread had errored with EAGAIN it was setting eof. I removed the set entirely, as there is no need for fgetc to even worry about it, fread will set the correct value in any case
updated test_stdin to work in SM shell
run test_stdin in all JS_ENGINES
Merge pull request #1555 from inolen/tty_fixes

added stubs for tcgetattr and tcsetattr, minor node tty fixes