* rename src directory to allocbench
* make global variable names UPPERCASE
* format a lot of code using yapf
* use lowercase ld_preload and ld_library_path as Allocator members
* name expected Errors 'err' and don't raise a new Exception
* disable some pylint messages

Now there is only a single plot function which takes a plot type as
well as some plot and figure options.

add new helper functions to get all y_values for a plot
use seperate figures for each plot
s/filepostfix/file_postfix/ to be consistent