Fixed #5941 (ValueFlow: Wrong value in subfunction under ?)
Fixed cppcheck warnings introduced by previous commit
Removed redundant code (replaced by libaries, should fix #5934).
valueFlowAfterCondition: wrong analysis for floats
runastyle: don't strip trailing spaces in cfg files. After a  'runastyle;git commit;git push', I get changes if I run runastyle again.

[ci skip]
Extended std.cfg about more missing functions. Moved POSIX functions to posix.cfg. Extended posix.cfg about more memory allocating functions.
Updated WiX installer and VS solution to VS12 and Qt5
Refactorizations optimizing std::string usage:
1) Added global const std::string emptyString; object. It is used for:
- Empty string passed to a function, which takes the parameter by reference
-> Avoids constructor call (std::string::string(""))
=> Reduces binary size (25% for testrunner.exe, 5% for cppcheck-core.dll)
=> Avoids unnecessary calls
- Functions, that return a string by reference
-> Even functions that return an empty string in some branches can return by reference now.

2) Added overloads for TestFixture::assertEquals for the most common use cases:
-> Moves conversion from const char[] to std::string into a function, reducing code duplication in binary.
Visual Studio: Use testsuite.h as precompiled header (compiled into testrunner.cpp)
-> Reduces build time of project testrunner by 13 seconds (16%)
Refactorization: Moved condition in Token::tokAt() out of loop.
Keep console open in testrunner
Use C++11 std::sto* instead of std::ato* where appropriate (emulated in cxx11emu.h)
Added AST validation