Cleanup static linking, fix MinGW GLEW linking
Fix a typo on README.md
Replace use of min(max(...), ...) with clamp(...)
Fix indentation in Dialog.cpp
Only warn once for unknown an compiler / OS
Move OS/distro detection out of ErrorReport.cpp

Also add support for /etc/os-release.
CrashHandlerPOSIX: Don't pre-fork a crash handler

Always starting a process to handle crashes is way too pessimistic
and there are so many other things that may go wrong (we are already
crashing after all), we may as well do an "unsafe" fork().
crashreporter: Turn off localization for gdb
Fix rotation offset when starting to drag objects
Remove unneeded <iostream> #includes
FindOpenALEFX.cmake: Look in ${OPENAL_INCLUDE_DIR}

So that we will find efx.h if AL is in a non-standard location.
FindGLEW.cmake: Use paths from pkg-config as hints
CMake: Add option abort on missing optional deps
CMake: Add separate option to enable debug output

Before this was coupled with CMAKE_BUILD_TYPE == Debug.

Also, change our debug #define from _DEBUG to ARX_DEBUG to not
conflict with other libraries.
Add an env var to adjust the data search path

$arx_PATH can now be set to a colon-separated (Windows: semicolon-
separated) list of paths to search for data files after the user path
and paths specified on the command-line, but before other system paths.
crashreporter: Ask users to provide detailed info
crashreporter: Add trailing slash to URL
Log the OpenAL vendor on startup

And add it to crash reports.
Log config file location on startup
Log the save game directory on startup