turn on rest of warnings flags on gnu compiler.
link order fix.
for example:
C:/MinGW/lib/libSDLmain.a;mingw32;C:/MinGW/bin/SDL.dll;C:/MinGW/lib/SDL_ttf.lib
->
mingw32;C:/MinGW/bin/SDL.dll;C:/MinGW/lib/libSDLmain.a;C:/MinGW/lib/SDL_ttf.lib
Merge pull request #8 from wagut/mingw-fix

Mingw fix
Revert "use Range instead of InputIterator"

This reverts commit 7d4b8b33eb5f084ef16b5d0ccbc58902c15fb0a1.
Revert "use Range instead of InputIterator"

This reverts commit fc982b5f6dcd063380c4c33f53ee634002f9ef24.
Revert "use Range instead of InputIterator"

This reverts commit a916dcd0d9f770c3af3f135a31a15f2bdbcf6ac8.
Revert "change unit_damage_all_collided to work on ranges"

This reverts commit f2aaa003d4610d1e21b10b2176200b52000be6cc.

Conflicts:
	src/unit.h
add support for more keys
shoot on space & tab
rename move_ship => move_ship_x
allow ships to move freely
add Escape key support
allow to restart game
allow specify font from outside of sdl/
allow to specify font size outside of sdl
make magic_offset less magic
rename {width => y}, why did I call it width?
make offset less magic
add SizeText to InvadersSystem
no more magic offsets