#14 Multiple issues with bltGrAxis.c

[goodegod]

I have discovered a couple of problems with the bltGrAxis.c file. The first is plotting to an axis that isn't shown, the element/marker will not show up. This is because Blt_HMap routine uses axisPtr->screenRange and screenMin, which are not set if the axis is not displayed. My solution is to use the graphPtr->hRange and hOffset.

The other issue is hidding an axis, then modifying the axis ranges. This will blow up the MakeSegments routine because the nMajorTicks may change, but the number of TickLables are not updated. The simple solution is to check the flags to determine if the axis is hidden.