Asammdf

Fixes
* update GUI to match the new API

Changes
* added _source_ argument to _get_ method

* in case of multiple channel name occurrence it allow to specify the wanted source
* if provided, it must match a channel's source name otherwise an exception is raised

Remove README.rst to avoid errors in conda-forge

Removes extra (unneeded) folders from the install package

Fixes
* documentation fixes
* many fixes

Changes
* backwards incompaltible API clean-up (some arguments have been renamed for consistency)
* refactoring of invalidation bits handling
* allow to instantiate MDF from file-like objects
* add _use_display_names_ keyword only argument to MDF classes. For MDF4, if False, it can speed up the file parsing considerably.
* MDF _scramble_ static method: scramble text blocks and keep original file structure (useful for privacy concerns when sending mdf files for debug purpose)

Changes
* mdf v3 code refactoring
* many documentation updates
* gui: improve advanced search results

Fixes
* lib: add logging NullHandler to avoid warning when no logging handler was set for 'asammdf'
* fix for issue 67
* fix for issue 68

Changes
* lib: add 'sync' argument to merge and concatenate methods
* gui: use ui without generated py files
* GUI can run with PyQt4 as well now
* gui: change line style on the current plot
* gui: make sure the cursor remains visible when moved using the left and right keys


Fixes
* fix setup.py to properly include files needed for GUI
* lib: fix MDF3 error when the file header had no comment