Simplified check registration:
- Use sorted insert instead of calling std::list<Check*>::sort() on each insertion
- Removed DJGPP/__sun hack in check.h (should be obsolete by our compiler requirements for C++11
Fixed #5677 (Fix overzealous substr() warning)
Try to avoid compiler warning for unary minus operator inside MathLib::toLongNumber<biguint>()
ValueFlow: Improved handling of bitand against a single-bit integer literal
Fixed typo in travis script and tools/readme.md, no functional change.
Convert MathLib::toLongNumber() from template member function to toLongNumber() and toULongNumber() to avoid various problems compiling with Visual Studio
Fixed some coverity findings about dead code, fixed a misleading comment
Code cleanup of stack depth tracking. Replaced class with simple POD variable.
Use constant instead of magic number for AST recursion limit

[ci skip]
astyle formatting

[ci skip]
Implemented a slower but shorter version of MathLib::isNullValue() as suggested by PKeuS. Removed not needed test cases. Improved doxygen documentation for MathLib::IsNullValue().
AST: Fixed iscast detection in '*((DWORD*)&buf[0])'
Fixed #5682 (False positive: (style) Same expression on both sides of '&&')
Tokenizer: Fixed bad simplifyComma for code 'a ? b = c , d : e ;'
#5684 The scope of the variable 'p' can be reduced - But it can not.
Add test to improve coverage of CheckIO::checkWrongPrintfScanfArguments()
Tokenizer: Fixed bad simplifyComma for code 'return a ? b = c , d : e ;'
updated posix.cfg
Fixed #5656 (false positive: (error) Possible null pointer dereference: f)
CheckMemoryLeak: moved 'popen' into posix scope