Fix crash on malformed file

Also remove outdated comment

Bug #65221
Merge remote-tracking branch 'origin/poppler-0.22'
Fix warning on narrowing conversion from int to DWORD

Fixes warning when compiling for Windows:

gfile.cc: In member function 'Goffset GooFile::size() const':
gfile.cc:609:30: warning: narrowing conversion of '-1' from 'int' to 'DWORD {aka long unsigned int}' inside { } is ill-formed in C++11 [-Wnarrowing]
LARGE_INTEGER size = {-1,-1};

https://bugs.freedesktop.org/show_bug.cgi?id=65239
Use ansi stdio extensions when using a mingw compiler

In the C runtime used by mingw compilers (msvcrt.dll) the printf
function does not support the C99 format-width specifier "%ll".

Defining __USE_MINGW_ANSI_STDIO enables mingw's ansi stdio extensions
that implement a C99 compliant printf function.

https://bugs.freedesktop.org/show_bug.cgi?id=65238
Fix printf format warning for size_t

Fixes:

  CXX    pdfunite.o
pdfunite.cc: In function ‘int main(int, char**)’:
pdfunite.cc:142:59: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘std::vector<Object>::size_type {aka long unsigned int}’ [-Wformat]

https://bugs.freedesktop.org/show_bug.cgi?id=65242
qt4: Fix test binary name in help
Add a pthread option to pdftoppm

It's mostly a developer tool only to test thread support
Not end user oriented (hence no buildsystem)

Parts also by Thomas
Add a thread stresser in qt4