add log4j-2 as logging tool and settle a log4j2.xml
add MiscellanesousUtils.simpleToString()
override toString() of RadialFunction2D and of implementations of RadialFunctionCore
override toString() of domain searchers
add Deprecated annotation to VisibleSupportDomainSearcher
add getNodesNum() in WeakformAssemblier and modify implemenations accordingly
override toString() in WeakformAssembliers
override toString() of MLS
refactor constructor of Mixer and PostProcessor into getters and setters
override toString() of Mixer
add info log in WeakformProcessor
add info log in WeakformProcessRunnable