Item13028: Implement --taint option on rewriteShebang

With unit tests.

Adds a new option   --taint / --notaint  or abbreviated -t -not  to
rewriteShebang.pl.   --taint option sets the perl -T taint checking
switch,   --notaint clears it.

Note that this option *only* changes the /bin directory.

Insert a space into configure_test so that rewriteshebang doesn't make
extra changes.