[BuildTools] --disable-pkg-config as default

[Stefan Vigerske]

Hi,

I'm thinking of changing the default of whether to use pkg-config to off
for BuildTools 0.7.
The reason is that I just recognized that pkg-config also may reorder
library flags if they are all given without -l/-L. I.e., I had
libcoinmetis.la end up in front of libcoinhsl.la.
Also specifying user library flags by not using the -l/-L syntax may
break something, as Andreas observed.
And under cygwin/cl, the examples won't work so far.

At least until the issue with the ordering of linker flags has been
resolved, I would thus make not using pkg-config default. The fallback
should be good enough for the usual builds, and one can still enable
pkg-config if one wanna build against installed libraries.

Stefan

-- 
Stefan Vigerske
Humboldt University Berlin, Numerical Mathematics
http://www.math.hu-berlin.de/~stefan