getxxx fu ret namedtuple, ipzfn getLDE, bug fix

1. Added code to few zGetxxx functions to return namedtuple instead of
tuples. This will provide better meaning to the returned variables in
interactive mode.
2. Added function ipzGetLDE(). It prints the rows of the LDE in IPython
notebook/qtconsole session.
3. Fixed a timing issue bug in _checkFileExist() function. Previously
the calling function could be blocked if the timeout was greater than a
second because the _checkFileExist() function compared only for
microseconds of the deltaTime. Now it compares seconds.