* Remove all dependencies of common code on doom/
    - net_client.c
 * Split d_iwad.c into common and use for Heretic/Hexen
 * Update netcode for new ticcmd_t fields
 * Chocolate Setup to allow configuration for H/H
 * Update docgen to generate manpages for Heretic/Hexen.

Heretic:
 * Fix bug with SFX played at wrong volumes
 * Multiplayer code to use Chocolate Doom multiplayer code.
 * Frequency shifted sounds.
 * Update input code to work properly with vanilla_keyboard_mapping
 * Check all command line parameters
 * Check for endianness assumptions
 * Savegame code to write structures predictably and endianness-correct
 * Remove NeXT and WATCOMC defines
 * Structure packing macros for structures read from disk
 * Merge r_draw.c to common version and delete duplicate
 * Recreate text mode startup using textscreen code.
 * v1.2 emulation (if possible)
 * Screensaver mode

Hexen:
 * CD-ROM music playback
 * Merge r_draw.c to common version and delete duplicate
 * Remove duplicates:
    - Skill levels
 * Multiplayer code to use Chocolate Doom multiplayer code.
 * WAD code to use the new locking API
 * Config file code to use m_config.c (and add H/H-specific variables)
 * Use the common i_sound API.  Frequency shifting?
 * Use the common cheats code
 * Update input code to work properly with vanilla_keyboard_mapping
 * Check for endianness assumptions (shouldn't be too bad if it was developed
   on NeXT)
 * Savegame code to write structures predictably and endianness-correct
 * Structure packing macros for structures read from disk
 * Screensaver mode