Fixed crash when checking tinyxml introduced by previous commit
Don't complain "could not find or open any of the paths given." if no arguments were passed to cppcheck (and help was shown)
Refactorizations:
- Removed some duplicate nullpointer checks
- Simplified tok->link() on '<' usage.
Refactorizations:
- Simplified pattern ".|->" to "."
- Use nextArgument() where appropriate
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.

Conflicts:
	lib/errorlogger.h
Updated solution to VS12
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.
Benchmark code
Use C++11 std::sto* instead of std::ato* where appropriate (emulated in cxx11emu.h)