hp-Adaptivity: Smoothness percentage control flexibility

[skvarjun]

User can control the percentage of smoothness values above which p-refinement is favored in hp-adaptivity. For instance, default value is set as 0.9, means p refining favored on an element only if local smoothness is above 90% when compared to the reported smoothness across all other elements. Important change is that an option argument Real smoothness_threshold = 0.9 is added to base class of select_refinement().

[moosebuild]

Job Coverage, step Generate coverage on 5281dfd wanted to post the following:

Coverage

	a65c5f	#4228 5281df
	Total	Total	+/-	New
Rate	64.54%	63.78%	-0.77%	100.00%
Hits	75858	74956	-902	4
Misses	41673	42575	+902	0

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Full coverage report

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