Subvesion requieres that every new file has these properties set. For example, you can set them on a per-file basis issuing the commands
svn propset svn:mime-type=text/plain
svn propset svn:eol-style=native
To automate the task, you can change subversions configuration file located at ~/.subversion/config. In this file make sure to uncomment the line
enable-auto-props = yes
and to add the following lines to the auto-props section
*.c = svn:mime-type=text/x-c++src;svn:eol-style=native
*.cxx = svn:mime-type=text/x-c++src;svn:eol-style=native
*.h = svn:mime-type=text/x-chdr;svn:eol-style=native
*.txx = svn:mime-type=text/x-c++src;svn:eol-style=native
*.txt = svn:mime-type=text/plain;svn:eol-style=native
On windows you can find the configuration file trhough the right-click menu of tortoise. Check here for more details