Install Apache Module X-Sendfile
Here's how I installed the module:


Download source code from [mod_xsendfile github repository)[https://github.com/nmaier/mod_xsendfile/releases]
Install a newer Apache via homebrew, i.e. brew install httpd (note: it will not remove or damage your current, Apple-provided apache install)
Go to sbin in apache dir, i.e. /usr/local/Cellar/httpd/2.2.23/sbin
Compile the module (as fat-module variant): 

./apxs -cia -Wc,"-arch i386 -arch x86_64" -Wl,"-arch i386 -arch x86_64" /path/to/mod_xsendfile.c

Restart apache.