[PATCH 0/9] handle alternate charsets for remote http errors

As of commit 426e70d (remote-curl: show server content on http errors, 2013-04-05), we relay any text/plain errors shown by the remote http server to the user. However, we were lazy back then and left this TODO in place:

       /*
        * We only show text/plain parts, as other types are likely
        * to be ugly to look at on the user's terminal.
        *
        * TODO should handle "; charset=XXX", and re-encode into
        * logoutputencoding
        */

This series actually implements that, along with a few other cleanups.

  [1/9]: test-lib: preserve GIT_CURL_VERBOSE from the environment
  [2/9]: strbuf: add strbuf_tolower function
  [3/9]: daemon/config: factor out duplicate xstrdup_tolower
  [4/9]: http: normalize case of returned content-type
  [5/9]: t/lib-httpd: use write_script to copy CGI scripts
  [6/9]: t5550: test display of remote http error messages
  [7/9]: remote-curl: recognize text/plain with a charset parameter
  [8/9]: strbuf: add strbuf_reencode helper
  [9/9]: remote-curl: reencode http error messages

-Peff