Description of problem:
starting Fedora 23, /usr/bin/latexpand started
triggering perl warnings on stderr.
this confuses scripts that parse stderr looking
for latex errors.

Version-Release number of selected component (if applicable):
texlive-latexpand-bin-svn27025.0-15.20140525_r34255.fc23.noarch

How reproducible:
always

Steps to Reproduce:
1. install full texlive
2. /usr/bin/latexpand 

Actual results:
$ /usr/bin/latexpand 
Unescaped left brace in regex is deprecated, passed through in regex; marked by <-- HERE in m/^[ \t]*\\end{ <-- HERE document}/ at /usr/bin/latexpand line 86.
Use of my $_ is experimental at /usr/bin/latexpand line 95.
Unescaped left brace in regex is deprecated, passed through in regex; marked by <-- HERE in m/^\s*\\usepackage{ <-- HERE ([^}]*)}\s*$/ at /usr/bin/latexpand line 137.
Unescaped left brace in regex is deprecated, passed through in regex; marked by <-- HERE in m/^(.*)\\bibliography{ <-- HERE ([^}]*)}(.*)$/ at /usr/bin/latexpand line 150.

Expected results:
no output should be produced.

Additional info:
this seems relevant
https://metacpan.org/pod/release/PCM/perl-5.21.3/pod/perl5211delta.pod#A-literal-should-now-be-escaped-in-a-pattern