Fix automatic search for dependencies when multiple instances of the
same library are installed in different prefixes that we search, by
using the first one found. Automatic search is only used when
pkg-config was not found. This fixes compiler errors caused by spurious
path names within compiler or linker flags, such as
ld: can't map file, errno=22 file '/usr/lib' for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see
invocation)
While here, also make XNU header version fallback more robust and add
(diabled) version mappings for 10.10.2 and 10.10.3 which are not
published by Apple yet.
Issue: #96
Reported by: Jan Vilhuber
Move from one set of headers per major OS X release to one set of
headers per XNU release. Fetch the header files from Apple's official
Open Source site instead of GitHub in the fetchdeps developer target.
As a side effect, 10.6.x is now supported as well (untested), and proper
headers are used for 10.10.
Issue: #39
