Revision 149

In invert_zoom_x, call rtsafe instead of the equivalent coding that
was there. funcd needs to access a[0-4] and abs_y so we upgrade a[0-4]
from arguments of coefpoly to variables of module coefpoly_m and abs_y
from local variable of invert_zoom_x to private variable of module
invert_zoom_x_m.

Removed unused arguments t10m and q10m of hbtm.