add CXXFLAGS for clang++ on OSX

Some C++11 features are only available on recent Apple
compilers (OSX 10.7+)
fix ini of QList and QStringList
replace std::initializer_list by QVector

clang doens't seem to linke the way it was.
add llvm std lib to linker

otherwise I get __next_prime symbol undefined
fix type redefinition

Lex.cpp:477:17: error: redefinition of 'c' with a different type: 'const char *' vs 'int'
add -lc++ to Xmi2Generator
git ignore .DS_Store
Merge pull request #68 from guitorri/osx

Mac OSX build adjustments