Merged from the 1.5 branch.


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@273204 13f79535-47bb-0310-9956-ffa450edef68

1. Removes the extraneous "cd `dirname $PRG`" line that causes the
    script to break when Ant is invoked with from a relative path
    (i.e. ../jakarta-ant/bin/ant).

2. Properly quote all environment variables that may contain paths.
    The script would break if any of these environment variables
    contained paths with spaces in them (a common occurrence on Windows).

3. Invoke Java using the "exec" shell command. There really is no need
    to create a child process to run the JVM and by using the "exec"
    command, there is less chance that killing the script will fail to
    kill Ant.

PR:
Obtained from:
Submitted by:	 Patrick Luby <patrick.luby@sun.com>
Reviewed by:


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@273200 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@270659 13f79535-47bb-0310-9956-ffa450edef68

May not fully build on *nix platforms yet.


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@268504 13f79535-47bb-0310-9956-ffa450edef68