fix zooming, order, y for the combination of 2 channels GPS_lk_Unlk and GPS_clock_power

closes #131 (closed) #127 (closed)

• Add x_top and x_bottom of GPS Lk/Unlk as attribute of ax to recalculate GPS Lk/Unlk's top and bottom total points when zooming after sohview switch to zoom by using matplotlib's lim.
• Solving #127 (closed) when linkedChan not point to an actual channel by using try except to by pass.
• Solving the case the channel and its linkedChan are plotted separately by moving the channel with linkedChan not move to the end to be plotted later when sohview using chan_order to for plotting order.
• Solving #131 (closed) when one of GPS Lk/Unlk has no value by preset ylim for the channel to -1, 1.
• Changing valueColors of GPS Clock Power to "1:C" so that the total point display color has the same color with the channel values.

UPDATE Parameters SET valueColorsB='1:C', valueColorsW='1:C' WHERE param='GPS Clock Power'