Fixes #2101, evaluation of text field and textarea line height.
Simplify DOM node walker.
Close file on error path.
Fix out of bounds array accesses for Cyrillic2 found by cppcheck.
Fix leak of filename found by cppcheck.
Fix leak of url found by cppcheck.
Avoid potential NULL ptr deref found by cppcheck.
Fix logic error found by cppcheck.
Fix logic error found by cppcheck.
Fix cppcheck bufferAccessOutOfBounds
Fix cppcheck syntaxError
Fix cppcheck nullPointer
Fix cppcheck syntaxError
Fix cppcheck nullPointer
Allow mouse tracking events to terminate without a PointerLeaving event being received.

This change should handle the situation where a PointerEntering event is received without a corresponding PointerLeaving event, which appears to be caused by some third-party OS addons. This could cause unexpected consequences, so all such terminations are currently logged.
Fix some cppcheck variableScope warnings
Remove cppcheck unnecessaryForwardDeclaration
Fix cppcheck variableHidingTypedef
Fix a bunch of cppcheck unusedVariable/unreadVariable warnings
Fix some cppcheck variableScope warnings