Prototype of Primerize_3D M2R Designs

• Added Mutation and Construct_List class for 2D and 3D algorithms;
• Renamed Design_1D to Design_Single, Design_2D to Design_Plate; Primerize_2D and Primerize_3D shares Design_Plate; class init now uses dict instead of a list of variables;
• Migrated primer filling for Primerize_2D into mutate_primers, shared with Primerize_3D;
• Renamed which_libs to which_lib.

Modify Primerize_2D.design() behavior

• Enable Primerize_2D.design() taking Design_1D() as input, and set this behavior as default;
• Add flag for forcing Primerize_2D.design() to run Primerize_1D.design() when manually input sequence, etc;
• Add mutation region display as an option in Design_2D().echo();
• Exclude plates with only WT well in Design_2D.save() for 'image' and 'excel';
• Use 3-digit well-position for Plate_96Well(), e.g. 'A01' instead of 'A1'.

support for python 3.x

1.1.2

solve import relative path

restructured classes

Major release for with restructured and annotated classes.
Updated README and LICENSE, ready for distribution.

primerize as python package

Made primerize as python package, i.e. enabling "import primerize".
Completed command-line argparse for primerze_1d and primerze_2d functions.
Disabled @jit "cache=True" due to setuptools install.