Ensure mktemp creates files in a apropiate directory

[MAProsper]

Currently all uses of mktemp in scripts use a template that generate the file at the current working directory. This directory may not be writeable, desirable to use and additionally in the event of a interruption or termination it leaves the file in a location where the system will probably not clean it up.

This could be fixed prepending the patten with ${TMPDIR:-/tmp}/. This selects an appropriate directory, follows the same logic as the default behaviour of mktemp and is compatible with coreutils's and busybox's mktemp implementation.