All files should have the Unix style (LF) line endings. Subversion should give an error if you try to commit a file with mixed line endings.
Please make the following change to your SVN config file (~/.subversion/config for Mac/Linux users). This will ensure that any new file with these extensions will automatically have the right line ending style set.
enable-auto-props = yes [auto-props] *.ini = svn:eol-style=LF *.php = svn:eol-style=LF *.css = svn:eol-style=LF *.js = svn:eol-style=LF
All of this should exist in the file by default, so you might just need to uncomment the auto-props line and add the extra lines at the bottom of the auto-props entries.
For TortoiseSVN, in the Settings dialog, General tab, Subversion section, there's an edit button for the config file. The auto-props stuff is near the bottom. You have to uncomment enable-auto-props and add the options to the auto-props section. Note that their parser doesn't seem to like leading spaces.