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 } ))
Merge pull request #242 from matthiaskrgr/travis

travis: compile with -Wunreachable-code .
Fixed #5469 (CheckBufferOverrun: Use nullptr)
Updated tinyxml
Library: the bug in tinyxml has been fixed so the workaround can be removed now