runningAverage functionality added

This method finds the running average of a linescan.Only the name of the algorithm has to be provided(either 'uniform' or 'gaussian') and the corresponding kernel is generated and convolved with the image.

Syntax:

    linescan.runningAverage(diameter=3,algo="uniform")

Example:

    import matplotlib.pyplot as plt
    ls = img.getLineScan(x=10)
    ra = ls.runningAverage()
    rag = ls.runningAverage(15,algo="gaussian")
    plt.plot(ls)
    plt.plot(ra)
    plt.plot(rag)
    plt.show()