Fix bug in vidMode_t constructor

it caused the default/static video mode list to contain only garbage
Improve R_GetModeListForDisplay()

* Fixed small bug when only one display mode was found by SDL2
* removed some redundant and dead code
* improved warnings
Renamed RBDoom3 to RBDoom3BFG
Updated README.txt with compile instructions for Linux
Updated README.txt
Disabled broken savegame and profile storage checks for the PC
Fixed error: class idLocalUserWin has no member named StorageSizeAvailable
Improve console behavior

* Pressing up and down again in the console will result in an empty line,
  not the stay at the last line from history
* Pressing up will really show the last command, not the last-but-one
Fix console on Linux

    * Add support for Console-Key independently of KB Layout (with scancode)
    * add support for TAB key
    * Add hack so console is empty after opening it (SDL-only)
Changed SAVE_PATH on Windows so we don't break the savegames of the original game.
restore SDL1-support in sdl_events.cpp

* add define for SDL_SCANCODE_GRAVE - seems like only SDL2
  has names for the values
* add some missing keys to SDL_KeyToDoom3Key
* add scancode to unmapped-key warning
* backspace needs to be handled the same for SDL1 as in SDL2
  (i.e. a new event must be created for it) to work in console
Fix scrolling in Menus for SDL2

scrolling didn't stop, e.g. in the resolution selection menu
Disabled usage of pthread_{get,set}_name because it does not work on all Linux systems.
Added support for precompiled headers for MSVC which reduced the compiled time from 4 minutes to 67 seconds.
Fixed Linux build.
Fixed various warnings from clang
Prevent segfault on shutdown

This should also happen on Windows, I'm really surprised
this hasn't been noticed there
Improve CMakeLists.txt

* manage warning flags in a variable, they're reused for
  each profile anyway (but this way profile-specific flags can
  still be added before or after the generic ones)
* added some disable-warning flags specifically for clang
Fix messed up view angle after taking screenshots

Pretty much like https://github.com/dhewm/dhewm3/issues/18
but here it took some more changes
Fixed MSVC C++ exception warnings