Default to clang for Mac
Merge remote-tracking branch 'origin/issue181' into epec-kernel

Conflicts:
	src/MainWindow.h
	src/ModuleCache.cc
	src/mainwin.cc
	src/module.cc
	src/module.h
	src/parsersettings.cc
	testdata/modulecache-tests/cascade.sh
	testdata/modulecache-tests/cascade2.sh
missed one conflict
Leftover from previous merge
clang fixes
Added missing include stdint.h to work with gcc 4.8.1

Without this include, this was not possible to build with gcc 4.8.1:

Build log (without this commit): http://kojipkgs.fedoraproject.org//work/tasks/1370/5521370/build.log
Merge pull request #413 from hroncok/patch-2

Added missing include stdint.h to work with gcc 4.8.1
Default to clang for Mac OS X 10.7+
Merge remote-tracking branch 'origin/epec-kernel'
gcc and clang profiles
Merge remote-tracking branch 'origin/epec-kernel'
Close file as soon as possible to avoid potential readlocks being kept too long. Might be enough for #415
check OPENSCAD_LIBRARIES first
renamed to setenv_mac-*
Removed a bunch of less useful tests
renamed dumptest files to .csg and added group headers
changed group headers to empty group headers

this became necessary because the batch editing in the last commit
didn't respect that an empty group is not group() { } but group();
trim precision in dumptest regressions

in order for them to work against openscad's .csg output, the number of
decimal places was reduced.
modify root modifier example now that the test program respects the root modifier

as the dumptests are now run from a full openscad, the root modifier is
respected by the test program too; reflectin that in the unit test
use openscad as a replacement for dumptest and echotest

the echotest and dumptest still contain hacks to keep the delta to the
original unit tests minimal; possibly, some of these changes will make
it into the openscad program, at which time they can go away from there.