HAproxy build improvements (#371)
HAproxy build improvements (#371)

* HAProxy: these options are all implied by TARGET=linux2628

* See Makefile line ~264:
  http://git.haproxy.org/?p=haproxy-1.6.git;a=blob;f=Makefile;h=0242caec3080f8e46d404c25f09e529fd1394b2f;hb=9c017e541bb3cee2e2884cdc53a4cb4627be5dad#l264

* HAProxy: let the Makefile find the right LDFLAGS

* HAProxy: -j4 doesn't mean much with make install

* It's just copying files

* HAProxy: Enable 2 more PCRE optimizations

* From the HAProxy Makefile:
* USE_REGPARM: enable regparm optimization. Recommended on x86.
* USE_STATIC_PCRE: enable static libpcre. Recommended.

vixns/marathon-lb,vixns/marathon-lb,mesosphere/marathon-lb,matt-deboer/marathon-lb,vixns/marathon-lb,mesosphere/marathon-lb,matt-deboer/marathon-lb,mesosphere/marathon-lb,matt-deboer/marathon-lb