When a binary mime-type is set on a file that looks like a text file,
make the 'svn' client print a warning about potential future problems
with operations such as diff, merge, and blame.

This is only done during local propset for now, because the file needs
to be present on disk to detect its mime-type.

See for related discussion: http://mail-archives.apache.org/mod_mbox/subversion-dev/201301.mbox/%3C20130131185725.GA13721%40ted.stsp.name%3E

* subversion/svn/cl.h
  (svn_cl__propset_print_binary_mime_type_warning): Declare.

* subversion/svn/propedit-cmd.c
  (svn_cl__propedit): Warn when a binary svn:mime-type property value is
   set on a local file that looks like text.

* subversion/svn/propset-cmd.c
  (svn_cl__propset): Warn when a binary svn:mime-type property value is
   set on a local file that looks like text.

* subversion/svn/util.c
  (svn_cl__propset_print_binary_mime_type_warning): New helper function.

* subversion/tests/cmdline/blame_tests.py
  (blame_binary): Adjust text expectations.

* subversion/tests/cmdline/commit_tests.py
  (commit_one_new_binary_file): Adjust test expectations.

* subversion/tests/cmdline/diff_tests.py
  (diff_force, diff_mime_type_changes): 

* subversion/tests/cmdline/info_tests.py
  (binary_tree_conflict): Adjust test expectations.

* subversion/tests/cmdline/merge_tests.py
  (merge_change_to_file_with_executable,
   merge_binary_file_with_keywords): Adjust test expectations.

* subversion/tests/cmdline/prop_tests.py
  (binary_mime_type_on_text_file_warning): New constant.
  (inappropriate_props): Adjust test expectations.

* subversion/tests/cmdline/svnlook_tests.py
  (diff_binary): Adjust test expectations.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1441814 13f79535-47bb-0310-9956-ffa450edef68