Not such important, important should be that when you add an extension you put the complete path, or, add as extension dir a directory that you know you will always copy in new compiled extensions.
PS. Not sure but ./ should be refered at /usr/local/lib OR (that should depend on how is installed php) /usr/local/php5/)
Someone should confirm/unconfirm my suppose, but for sure what i wrot ein first line is totally valid.
Regards