syntaxerr: missing r'literal' for unset PS1
PR #66: TypeError thrown by spawnu.readline()

Submitted by @auntieNeo, fixes exception, "TypeError:
got <type 'str'> ('\r\n') as pattern" in spawnu.readline().

Bytes b'\r\n' was concatenated to u'unicode', causing an
exception to be thrown when using readline().
Minor fixes for replwrap tests
Make execute permission check more explicit
Merge pull request #71 from pexpect/replwrap-test-fixes

Fixing various prompt issues with bash ReplWrapper
Merge pull request #70 from pexpect/more-exacting-which

new function is_exe() makes existing which() more correct
Improve EOF through test -> interact -> echo_prompt
Document and detect EOF condition in interact()
python3.2 accommodations
For python3, exceptions should use "as err", not ", err"
Make a modified copy of os.environ for interact tests
Merge pull request #72 from pexpect/interact-does-not-detect-eof

Interact() does not detect EOF
Solaris support, tested on SmartOS from cron(1).
Missing time import -- there is no 'waitecho' function

although I am against most time.sleep()s and trying my best
to remove them where possible, there is no opposing
waitnoecho() function (perhaps we should supply one?).
Another "as err" vs ", err" exception fix.

as well as another indent-by-4 fix