corrected bug where format of dfrac was incorrect, now treated as a string to ensure formatting is preserved.
precision set to 6 as that is required to ensure printing of mpc dates are high-enough precision to capture fractional seconds.  Also corrected the order of comparison in the 'Equals' assert.
ignore all the .idea files which pycharm creates/add
Fixes #126 by correcting dfrac to be formated as string.  Also fixed bug with magnitude and trailinng 0 and aded a class factory method '.from_string' to build Observations from an input string
added test of Observation.from_string factory method
added .idea to excluded path
Merge branch 'mpc' of http://github.com/ijiraq/MOP into mpc
Merge branch 'mpc' into integrate_mpc_changes
MPCWriter's write_mpc_line method now takes an mpc.Observation
object as its parameter.
Pass note1/note2 code to mpc.Observation instead of full note 
description.