0.5-pr1

• Added the bxt_record command which records a demo asap (to be used like: bxt_record mydemo;map c1a0).
• Added the bxt_autopause cvar. If set to 1, automatically pauses the game on loads (to be used for segmenting).
• Added the bxt_show_hidden_entities cvar, set it to values 1 through 3 to show different categories of hidden entities (higher means more entities shown).
• Added the _bxt_min_frametime cvar which acts as fps_max but works with host_framerate. Also it accepts frametime instead of FPS, so where you would set fps_max to x you need to set _bxt_min_frametime to 1 / x.