more stability fixes for mlaunch around restarting already initialized environments.

This failed before:

mlaunch --replicaset
mlaunch --replicaset
added a very short sleep (100ms) at the end of a stop command. There is a short period
where the process is not reachable anymore but the socket is not torn down fully yet.
added test to error out cleanly when no log file is provided for mlogfilter.
Give clear error when mlogfilter is called without any log file. Fixes #124.
increased time limit of slow test because it was failing on travis.
renamed .logfile to .filehandle in LogFile.
added a log file that has a roll over from Dec 30 to Jan 2.
added test for util/logfile.py with first test.
added test for .start and .end properties.
added __iter__ and __len__ methods. iteration over a LogFile will yield a LogLine object per line in the file.

also fixed a bug with the number of lines being off by one.
Started writing a spec for mgenerate.
added some more operator stubs to mgenerate spec.
For --authentication, add user
fixed --version in mlaunch. added a test for all tools.
small bug for customized LogLine creation.
added code to convert profile collection to fake logfile.
added spec for $array, $choose, $missing.
added "ratio" parameter to $choose.
added some more details to spec and first implementation of some operators.
added late evaluation for some operators ($choose, $missing) for more intuitive behavior.