* fixed TypeError in settings which can be triggered when the settings
  are opened for the first time.

* added functionality to settings
* minor debug of annotation function

* cleaned-up signalization in __main__ (reallocated some calls from
  matplotlib directly to Qt)
* separated image painting for printing and copying to separate file

* zcetools now support negative ions
* fixed glitches in annotation

* zcetools got broken by previous commits to graphtools, fixed it.

* Printing is not perfect, but it is somehow working

* Experimental printing support
* Added script to generate icon python resource

* rewritten populate and plot_subtime functions in graphtools
* rewritten autozoomy function
* slightly modified the update_spectrum function in __main__
* rewritted the peak picking function
* removed debug prints from the last commit

* changed layout of the QSettings
* added functions for intensity annotation and some memory of user
  preferences

* lines less thick to improve visibility
* added dirview under treeview for quick sweeps

* Fixed if statement in autozoomy
* Masses prediction now calibrated to the main mass

* Now prasopes can predict isotope pattern and plot it into parent
spectrum
* autozoom Y axis action double click in absence of the spectrum now
does not cause exception

* New dock of treefolderview
* fixed bug in drltools window closing

* before they did not reacted to new file opening

* hopefully no more reference before assigment

* fixed signal issues when loading DRL from cache (long-time bug)
* reformatting (less-sphagetti in DRL)
* loading of files by dropping and cli fixed (broken in v0.0.3)

forgot to do it on previous update

* incorporate through pyqt signals
* ZCE dialog has its own logger now

* About dialog now shows version for easy-check
* Minor fix of DRL export formatting (name without space)
* Set version to 0.0.2 (will now increment on any bigger update)

* added end-time cut off to the time selection in DRL

* Fixed export which has been broken by previous patch

* Now it accepts also files with 0 correction factors in daughter table.

* purging graph completely before populating, otherwise matplotlib has autoscale issues

* saving of the DRL table and exporting datasets now originates in a logical location
* fixed timeshift misplacement in the exported table
* when adding line the peakwidth is copied from the line above

* better algorithm to detect incompatible files when loading DRL table
* fixed bug which caused crashes when increasing columncount
* reduced workload when descreasing columncount

* changed the ion selection from start m/z-end m/z to m/z-peak width.

* loading of the incompatible file will not crush whole program
* moved to GridSpec layout - constrained layout preparation

* amount of "correct to" columns can be changed now in a software itself
* fix for deletion of multiple rows - now the SW survives
* time shift is now noted in the exported file (has been done in
previous commit, forget to note it)

* columns for "correct to" selection are now responsive as they should

* daughter ion table is more responsive
* we are not dividing by zero anymore (at least I hope)