Splayout

* Pixels region for inverse design.
* Variable names: point1 -> bottom_left_corner_point, point2 -> top_right_corner_point.

* Able to derive phase information from monitor.
* Able to create rectangle&circle pixels with fdtd functions.

* README.rst for pypi ducumentation.
* Support numpy array for Polygon definition.
* Annotation for DBS run.
* Support cell flatten.
* Fix a bug: initial_solution in DirectBianrySearchAlgorithm can not be properly defined.

* FDTD API added.
* Binary Bat Algorithm & Direct Binary Search Algorithm for inverse design.

* SBend docs update.
* Variable names: angle -> radian.
* AEMD gratings can have multiple definitions in a file.
* AEMD Grating default relative position: RIGHT.
* New cell function: self.remove_components().
* If the input filename of "make_gdsii_file" is not "*.gds", it will automatically add ".gds" to the tail.
* New class: Circle, Rectangle.
* Add port points definition for Polygon.

* Add self.get_start_point() for AEMD_grating.
* New Class: SBend & ASBend.
* Add a constant: pi = math.pi.