BUGFIX: First try of fixing missing data bug for customBars and errorBars
TEST: test to verify the bugfix
REFACTORING: moved option retrieving out of the for loop for better
performance.
TEST: Added examples for the bugfix.
BUGFIX: added missing spaces.
TEST: Added automatet tests for customBar and errorBar options and missing data points.
REFACTORING: Changed if / else cases to optimize the performance for the
default cases.
TEST: Added NaN cases to the missingPoints test.
Merge pull request #245 from sauter-hq/custom-bar-data-gaps-459

Custom bar data gaps 459