[Gpsbabel-code] malloc procedures

[Robert L. <rob...@us...>]

Since gpsbabel is a short-running program and even the largest data sets
should easily fit within memory (real or virtual) on any interesting host,
always feel free to dynamically allocate memory and treat it as a fatal
error if that allocation fails.   No data should ever really be lost as
gpsbabel is always converting from something to something else.