tools/version.sh: Use backup files on Win32
tools/version.sh: Use backup files on Win32

Copied from corresponding change in jgit repository.
Windows doesn't permit us to edit a file in-place with Perl.
So create backup files when we perform the edit, and remove them
when we are done.  This is a tad slower on POSIX systems, but is
much more portable.

Change-Id: Ib267092d47b115972139c8ae367acee572d62ccf
Also-by: Shawn O. Pearce <f01032651c12a22b2103346ba96b3b6b231f9d3c@spearce.org>
Signed-off-by: Matthias Sohn <446760a3fbea85cd5f8f4f5c3de304fe3a38014f@sap.com>

jdcasey/EGit,paulvi/egit,mdoninger/egit,bols-blue/eclipse_maven_autobuild_sample,SmithAndr/egit,collaborative-modeling/egit,blizzy78/egit,chalstrick/egit,SmithAndr/egit,rickard-von-essen/egit,jdcasey/EGit,wdliu/egit,rickard-von-essen/egit,collaborative-modeling/egit,paulvi/egit,wdliu/egit,bols-blue/eclipse_maven_autobuild_sample