FileJoin - Combines directory/file names in correct format for current platform.
SYNOPSIS
FileJoinname1 name2 ...
DESCRIPTION
This prcedure is basically an interface to the Tcl file join command. The input is two or
more directory names, and the final name may be a file name. These are combined using the correct path
separator for the current platform. Unlike the file join command this procedure will handle
if the first argument is an environment variable (e.g. $FOO) or a reference to a user's
home directory (e.g. ~fred). For example:
FileJoin $CCP4I_top tasks fft.tcl
will return (on a Unix platform)
/usr/local/bin/ccp4/ccp4i/tasks/fft.tcl