pkg/45758: audio/esound: add configure check for esound

[matthias.rampke%googlemail.com@localhost]

>Number:         45758
>Category:       pkg
>Synopsis:       audio/esound: add configure check for esound
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Dec 29 23:55:00 +0000 2011
>Originator:     Matthias Rampke
>Release:        DragonFly HEAD
>Organization:
>Environment:
DragonFly tp.2pktfkt.net 2.13-DEVELOPMENT DragonFly 
v2.13.0.623.g2c104-DEVELOPMENT #0: Wed Dec 21 06:48:14 UTC 2011     
root%pkgbox32.dragonflybsd.org@localhost:/usr/obj/usr/src/sys/GENERIC  i386
>Description:
esound does not check for if an explicit -lm is needed. The attached patch adds 
the appropriate configure check
>How-To-Repeat:
build on DragonFly
>Fix:
https://gist.github.com/1536749

I couldn't find an easy way to patch this into 'configure' directly, so I had 
to take a detour with autoreconf. I'd rather avoid adding the additional steps 
and dependencies, so a simpler patch would be welcome.