Log Message:
Upgrade esound to 0.2.33.

Changes:

        * use new ALSA PCM API if available (Lukasz Mach and Eddy Mylyono)
        * fix build on AIX and OSF (Albert Chin-A-Young)
        * don't try to close audio device if not opened (Debian)
        * fix build with latest automake (Stanislav Bradec)
        * no longer required automake 1.4 (Thomas Cataldo)
        * Fix Darwin build (Jerry Talkington)
        * fix typo in manpage (Kjartan Maraas)

While here use subst.mk instead of patching configure script.