plgchr: Get character default height and current
(scaled) height 

DESCRIPTION:

    Get character default height and current (scaled) height. 

SYNOPSIS:

plgchr(p_def, p_ht)

ARGUMENTS:

    p_def (PLFLT *, output) :     Pointer to default character height (mm). 

    p_ht (PLFLT *, output) :    Pointer to current (scaled) character
    height (mm).