Fails to build on OS X

[sebastiang]

Installing LMDB results in the following errors on OS X. (Yosemite OS X 10.10.3/XCode 6.3). I was surprised to see it building an so and not a dylib, but I'm no expert.

gcc -fPIC -shared -pthread -O2 -g -W -Wall -Wno-unused-parameter -Wbad-function-cast ../src/wrapper.c /Users/sebastian/.julia/v0.4/LMDB/deps/src/lmdb-0.9.14/mdb.c /Users/sebastian/.julia/v0.4/LMDB/deps/src/lmdb-0.9.14/midl.c -o liblmdbjl.so -I/Users/sebastian/.julia/v0.4/LMDB/deps/src/lmdb-0.9.14
gcc: warning: couldn’t understand kern.osversion ‘14.3.0
mkdir -p ../usr/lib
cp liblmdbjl.so ../usr/lib
rm *.so
=============================================[ ERROR: LMDB ]==============================================

LoadError: Provider BinDeps.BuildProcess failed to satisfy dependency liblmdbjl
while loading /Users/sebastian/.julia/v0.4/LMDB/deps/build.jl, in expression starting on line 38

==========================================================================================================

[wildart]

I newer got hand on a multi-platform support. I just pushed fix that should solve this issue.