Revert "cxx11.h: removed the 'evil workaround'"

This reverts commit 2cb9032d76e2a6751b2b2a9458c6823e23fa1e21.
daca2: tell wget to overwrite file. We want that the correct file is used.
Fixed #5301 (False positive: (error) Division by zero - variables read from input stream)
Fixed #5434 (FP: Out-of-bounds access with ternary operator in loop)
#5304: added a losts of TODO testcases for MathLib::isFlot().
#5304: added a losts of TODO testcases for MathLib::isFloat().
TestMathLib: added robustness tests for testing MathLib::isFloat. Ensure it works correctly for preceeding and trailing white spaces.
daca2: fixed wget function
ci.py: fixed daca2folder() when results is empty
Fixed #5381 (Some false positives that came up when using --enable=performance file.c)
AST: improved AST printout when --verbose is used
Fixed #5304 (Wrong simplification of numbers like 001E+07 to 1.0)
Fixed #5452 (AST: wrong handling of unary ::)
Fixed #5493 (False positive: Found a statement that begins with numeric constant / string constant - in the presence of initialization list.)
Fix Cppcheck warning
Fixed #5492 (Fix small bug in MathLib::isFloat())
travis: compile with -Wunreachable-code .
Spell fix: dont => do not
htdocs: update visual studio plugin link
Fixed #5166 (segmentation fault (invalid code) in lib/checkother.cpp:329 ( void * f { } void b ( ) { * f } ))