Cache results for TokenList::isC() and TokenList::isCPP() to avoid redundant calls to Path::isCPP()/isC(), which perform slow string operations (conversion to lowercase, substring, comparisons)
-> Speedup of 2% on self-checking cppcheck-core (MSVC12, x64, not matchcompiled)
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.
std.cfg: Added support for more functions.
Extended std.cfg, posix.cfg and avr.cfg
Fixed #5947 (valueFlowForward: forward conditions not handled properly)
Speedup Tokenizer::simplifyMathFunctions() and Tokenizer::simplifyPlatformTypes()
-> Speedup on entire checking time (TortoiseSVN code) by 3% (MSVC12, x64, not matchcompiled). Probably only measurable when checking code with Windows platform.
Optimized Tokenizer::simplifyPlatformTypes() once more: Another 3% improvement on Windows.
-> All Token::Match strings are uppercase, so check Token::isUpperCaseName() to avoid comparisons with very slow long Token::Match strings (idea from amai)
Removed duplicate Token::Match call in symboldatabase.cpp