Splotch

* Fixed issue with tuple-defined linestyles
* Fixed confusion when using RGB/RGBA tuples when drawing multiple lines.

* Changed sector() to cause rotate to act in a clockwise direction
* scatter() now returns a list of PathCollections

* Added colorbar() function to axis_func.py which acts as a utility wrapper around plt.colorbar()
* splt.colorbar() acts on any currently drawn mappables with simplified methods of giving coloarbar location

* Fixed bug in curve() when no substitute variables are specified

* Updated axline(), brokenplot(), curve() and plot() to return their corresponding Line2D objects
* If multiple lines produced in these functions, instead return a list of Line2D objects
* brokenplot() will always return a list of tuple pairs corresponding to the lines on either side of the axis break
* Updated brokenplot() to now remove any duplicate ticks if they appear

* Fixed issue when specifying colours as RGB/RBGA tuples in base_funct.dict_splicer()