#12 compiler detection breaks when using clang

[Hanspeter Niederstrasser]

On OS X 10.7+, where clang is the default compiler (and gcc has been fully removed in 10.9), configure misidentifies clang:

checking dependency style of g++... gcc3

When using gcc, you need to have gcc >= 4.6.x. You have only 4.2.1, aborting.

These are the reported versions on 10.9 with Xcode 6:

$ clang --version
Apple LLVM version 6.0 (clang-600.0.51) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin13.4.0
Thread model: posix
$ clang -dumpversion
4.2.1

[Bastien Chevreux]

MIRA 4.0.x supports only gcc atm, please use that for the time being.

clang support has been added to the development version of MIRA, I expect a first public tarball with 4.1.0 to be ready in a couple of weeks.