unset PROMPT_COMMAND in replwrap and test_replwrap

which issues set-xterm-title terminal sequence on many systems,
causing unrelated output to be received.
catch exceptions explicitly
only SkipTest on IOError on setecho & friends for sunos
Merge branch 'issue-44-solaris-try-2' of git+ssh://github.com/pexpect/pexpect into issue-44-solaris-try-2

Conflicts:
	tests/test_misc.py