SDL2: combine SDL_KEYDOWN events directly with following SDL_TEXTINPUT events when...

SDL2: combine SDL_KEYDOWN events directly with following SDL_TEXTINPUT events when possible.

This solves ` keypresses that open/close the console also typing in a character
"once and for all". The ability to type the ` character into the console is not
impaired by this as con_closeontoggleconsole's logic to by default ignore the
toggleconsole key when in the console but not at the beginning of the line
still applies.

From: terencehill <piuntn@gmail.com>

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@12335 d7cf8633-e32d-0410-b094-e92efae38249
::stable-branch::merge=50312b15cfb7bd198d25aef3e999effe67e67b4e